mariadb/mysql-test/suite/innodb/t/instant_alter.test

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MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
--source include/innodb_page_size.inc
--source include/have_sequence.inc
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
let $datadir=`select @@datadir`;
SET @save_stats_persistent = @@GLOBAL.innodb_stats_persistent;
SET GLOBAL innodb_stats_persistent = 0;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
--echo #
--echo # MDEV-11369: Instant ADD COLUMN for InnoDB
--echo #
MDEV-20590 Introduce a file format constraint to ALTER TABLE If a table is altered using the MDEV-11369/MDEV-15562/MDEV-13134 ALGORITHM=INSTANT, it can force the table to use a non-canonical format: * A hidden metadata record at the start of the clustered index is used to store each column's DEFAULT value. This makes it possible to add new columns that have default values without rebuilding the table. * Starting with MDEV-15562 in MariaDB Server 10.4, a BLOB in the hidden metadata record is used to store column mappings. This makes it possible to drop or reorder columns without rebuilding the table. This also makes it possible to add columns to any position or drop columns from any position in the table without rebuilding the table. If a column is dropped without rebuilding the table, old records will contain garbage in that column's former position, and new records will be written with NULL values, empty strings, or dummy values. This is generally not a problem. However, there may be cases where users may want to avoid putting a table into this format. For example, users may want to ensure that future UPDATE operations after an ADD COLUMN will be performed in-place, to reduce write amplification. (Instantly added columns are essentially always variable-length.) Users might also want to avoid bugs similar to MDEV-19916, or they may want to be able to export tables to older versions of the server. We will introduce the option innodb_instant_alter_column_allowed, with the following values: * never (0): Do not allow instant add/drop/reorder, to maintain format compatibility with MariaDB 10.x and MySQL 5.x. If the table (or partition) is not in the canonical format, then any ALTER TABLE (even one that does not involve instant column operations) will force a table rebuild. * add_last (1, default in 10.3): Store a hidden metadata record that allows columns to be appended to the table instantly (MDEV-11369). In 10.4 or later, if the table (or partition) is not in this format, then any ALTER TABLE (even one that does not involve column changes) will force a table rebuild. Starting with 10.4: * add_drop_reorder (2, default): Like 'add_last', but allow the metadata record to store a column map, to support instant add/drop/reorder of columns (MDEV-15562).
2020-03-30 12:31:54 +03:00
SET @saved_allowance = @@GLOBAL.innodb_instant_alter_column_allowed;
2020-03-30 14:50:23 +03:00
SET GLOBAL innodb_instant_alter_column_allowed = DEFAULT;
MDEV-20590 Introduce a file format constraint to ALTER TABLE If a table is altered using the MDEV-11369/MDEV-15562/MDEV-13134 ALGORITHM=INSTANT, it can force the table to use a non-canonical format: * A hidden metadata record at the start of the clustered index is used to store each column's DEFAULT value. This makes it possible to add new columns that have default values without rebuilding the table. * Starting with MDEV-15562 in MariaDB Server 10.4, a BLOB in the hidden metadata record is used to store column mappings. This makes it possible to drop or reorder columns without rebuilding the table. This also makes it possible to add columns to any position or drop columns from any position in the table without rebuilding the table. If a column is dropped without rebuilding the table, old records will contain garbage in that column's former position, and new records will be written with NULL values, empty strings, or dummy values. This is generally not a problem. However, there may be cases where users may want to avoid putting a table into this format. For example, users may want to ensure that future UPDATE operations after an ADD COLUMN will be performed in-place, to reduce write amplification. (Instantly added columns are essentially always variable-length.) Users might also want to avoid bugs similar to MDEV-19916, or they may want to be able to export tables to older versions of the server. We will introduce the option innodb_instant_alter_column_allowed, with the following values: * never (0): Do not allow instant add/drop/reorder, to maintain format compatibility with MariaDB 10.x and MySQL 5.x. If the table (or partition) is not in the canonical format, then any ALTER TABLE (even one that does not involve instant column operations) will force a table rebuild. * add_last (1, default in 10.3): Store a hidden metadata record that allows columns to be appended to the table instantly (MDEV-11369). In 10.4 or later, if the table (or partition) is not in this format, then any ALTER TABLE (even one that does not involve column changes) will force a table rebuild. Starting with 10.4: * add_drop_reorder (2, default): Like 'add_last', but allow the metadata record to store a column map, to support instant add/drop/reorder of columns (MDEV-15562).
2020-03-30 12:31:54 +03:00
2019-07-16 15:42:36 +03:00
call mtr.add_suppression("Cannot add field `.*` in table `test`.`.*` because after adding it, the row size is");
let $format= `SELECT CASE WHEN @@GLOBAL.innodb_page_size>16384
THEN 'DYNAMIC' ELSE 'COMPRESSED' END`;
CREATE TABLE t(a INT UNIQUE)ENGINE=InnoDB ROW_FORMAT=COMPACT;
eval ALTER TABLE t ADD e INT, ROW_FORMAT=$format;
INSERT INTO t SET a=1;
SET @old_instant=
(SELECT variable_value FROM information_schema.global_status
WHERE variable_name = 'innodb_instant_alter_column');
--enable_info
ALTER TABLE t ADD b INT NOT NULL, ALGORITHM=COPY;
ALTER TABLE t ADD c INT NOT NULL, FORCE;
--disable_info
SELECT variable_value-@old_instant instants
FROM information_schema.global_status
WHERE variable_name = 'innodb_instant_alter_column';
--enable_info
ALTER TABLE t ADD d INT NOT NULL;
--disable_info
SELECT * FROM t;
SHOW CREATE TABLE t;
SELECT variable_value-@old_instant instants
FROM information_schema.global_status
WHERE variable_name = 'innodb_instant_alter_column';
SELECT variable_value-@old_instant instants
FROM information_schema.global_status
WHERE variable_name = 'innodb_instant_alter_column';
DROP TABLE t;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
connect analyze, localhost, root;
connection default;
SET timestamp = 42;
SET time_zone='+03:00';
SET @old_instant=
(SELECT variable_value FROM information_schema.global_status
WHERE variable_name = 'innodb_instant_alter_column');
let $format= 3;
let $redundant_4k= `SELECT @@GLOBAL.innodb_page_size=4096`;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
while ($format) {
let $engine= `SELECT CONCAT('ENGINE=InnoDB ROW_FORMAT=',CASE $format
WHEN 1 THEN 'DYNAMIC'
WHEN 2 THEN 'COMPACT'
ELSE 'REDUNDANT' END)`;
eval CREATE TABLE t1
(id INT PRIMARY KEY, c2 INT UNIQUE,
c3 POINT NOT NULL DEFAULT ST_GeomFromText('POINT(3 4)'),
SPATIAL INDEX(c3)) $engine;
INSERT INTO t1 (id, c2) values(1,1);
2017-11-23 15:02:26 +02:00
SELECT id,c2,ST_AsText(c3) c3 FROM t1;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
--enable_info
ALTER TABLE t1 ADD COLUMN (
d1 INT, d2 INT UNSIGNED DEFAULT 10, d3 VARCHAR(20) NOT NULL DEFAULT 'abcde',
d4 TIMESTAMP NOT NULL DEFAULT current_timestamp());
ALTER TABLE t1 ADD INDEX(d3);
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
--disable_info
BEGIN;
UPDATE t1 SET d3='';
ROLLBACK;
2017-11-23 15:02:26 +02:00
SELECT id,c2,ST_AsText(c3) c3, d1, d2, d3, d4 FROM t1;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
INSERT INTO t1 (id) VALUES(2),(3),(4),(5),(6);
--enable_info
ALTER TABLE t1 CHANGE d1 d1 INT DEFAULT 5, CHANGE d2 d2 INT DEFAULT 15,
CHANGE d3 d3 VARCHAR(20) NOT NULL DEFAULT 'fghij',
CHANGE d4 dfour TIMESTAMP NOT NULL DEFAULT now();
--disable_info
UPDATE t1 SET d3='foo' WHERE id = 2;
UPDATE t1 SET d3=DEFAULT WHERE id = 4;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
INSERT INTO t1 SET id = 7;
2017-11-23 15:02:26 +02:00
SELECT id,c2,ST_AsText(c3) c3, d1, d2, d3, dfour FROM t1;
CHECK TABLE t1;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
# add virtual columns
--enable_info
ALTER TABLE t1 ADD COLUMN e1 INT AS (id * 3);
ALTER TABLE t1 ADD COLUMN e2 VARCHAR(30) AS (d3);
ALTER TABLE t1 ADD COLUMN e3 INT AS (id * 2);
# instant alter
ALTER TABLE t1 CHANGE d3 d3 VARCHAR(20) NOT NULL DEFAULT 'foobar',
ADD COLUMN (d5 CHAR(20) DEFAULT 'hijkl', d6 INT DEFAULT -12345, d7 INT),
DROP INDEX d3;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
--disable_info
INSERT INTO t1 SET id = 8;
# Updating a column by extending an existing record
UPDATE t1 SET d3 = 'yyyyy' WHERE id = 1;
# Updating an already materialized column
UPDATE t1 SET d3 = 'xxxxx' WHERE id = 2;
# transaction rollback
BEGIN;
UPDATE t1 SET d3 = 'xxxxx' WHERE id = 3;
2017-11-23 15:02:26 +02:00
SELECT id, c2, ST_AsText(c3) c3, d1, d2, d3, dfour, e1, e2, e3, d5, d6, d7 FROM t1 WHERE id = 3;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
ROLLBACK;
2017-11-23 15:02:26 +02:00
SELECT id, c2, ST_AsText(c3) c3, d1, d2, d3, dfour, e1, e2, e3, d5, d6, d7 FROM t1 WHERE id = 3;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
# NULL to NULL, no change
BEGIN;
UPDATE t1 SET d7 = NULL WHERE ID = 5;
ROLLBACK;
BEGIN;
UPDATE t1 SET d7 = NULL, d6 = 10 WHERE id = 5;
2017-11-23 15:02:26 +02:00
SELECT id, c2, ST_AsText(c3) c3, d1, d2, d3, dfour, e1, e2, e3, d5, d6, d7 FROM t1 WHERE id = 5;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
ROLLBACK;
2017-11-23 15:02:26 +02:00
SELECT id, c2, ST_AsText(c3) c3, d1, d2, d3, dfour, e1, e2, e3, d5, d6, d7 FROM t1 WHERE id = 5;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
# add virtual stored columns; not instant
--enable_info
ALTER TABLE t1 ADD COLUMN (f1 VARCHAR(20) AS (concat('x', e2)) STORED);
# instant add
ALTER TABLE t1 ADD COLUMN (d8 VARCHAR(20) DEFAULT 'omnopq');
--disable_info
2017-11-23 15:02:26 +02:00
SELECT id, c2, ST_AsText(c3) c3, d1, d2, d3, dfour, e1, e2, e3, d5, d6, d7, f1, d8 FROM t1;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
SHOW CREATE TABLE t1;
--enable_info
ALTER TABLE t1
CHANGE c2 c2 INT DEFAULT 42,
CHANGE d1 d1 INT DEFAULT 1,
CHANGE d2 d2 INT DEFAULT 20,
CHANGE d3 d3 VARCHAR(20) NOT NULL DEFAULT 'boofar';
--disable_info
INSERT INTO t1 SET id=9;
--enable_info
ALTER TABLE t1 DROP c3;
--disable_info
SHOW CREATE TABLE t1;
SELECT * FROM t1;
eval CREATE TABLE t2
(id INT primary key, c1 VARCHAR(4000),
p GEOMETRY NOT NULL DEFAULT ST_GeomFromText('LINESTRING(0 0,0 1,1 1)'),
SPATIAL INDEX(p))
$engine;
BEGIN;
INSERT INTO t2 SET id=1, c1=REPEAT('a', 4000);
INSERT INTO t2 SET id=2, c1=REPEAT('a', 4000), p=ST_GeomFromText('POINT(1 1)');
COMMIT;
--enable_info
ALTER TABLE t2 ADD COLUMN d1 VARCHAR(2000) DEFAULT REPEAT('asdf',500);
--disable_info
2017-11-23 15:02:26 +02:00
SELECT id, c1, ST_AsText(p) p, d1 FROM t2;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
# inplace update, rollback
BEGIN;
UPDATE t2 SET c1 = repeat(id, 4000);
connection analyze;
ANALYZE TABLE t2;
SELECT clust_index_size FROM INFORMATION_SCHEMA.INNODB_SYS_TABLESTATS
WHERE name = 'test/t2';
connection default;
ROLLBACK;
connection analyze;
ANALYZE TABLE t2;
SELECT clust_index_size FROM INFORMATION_SCHEMA.INNODB_SYS_TABLESTATS
WHERE name = 'test/t2';
connection default;
# non-inplace update. Rollback MUST NOT materialize off-page columns.
BEGIN;
UPDATE t2 SET d1 = repeat(id, 200);
connection analyze;
ANALYZE TABLE t2;
SELECT clust_index_size FROM INFORMATION_SCHEMA.INNODB_SYS_TABLESTATS
WHERE name = 'test/t2';
connection default;
ROLLBACK;
connection analyze;
ANALYZE TABLE t2;
SELECT clust_index_size FROM INFORMATION_SCHEMA.INNODB_SYS_TABLESTATS
WHERE name = 'test/t2';
connection default;
2019-11-14 13:22:29 +02:00
if ($redundant_4k)
{
--error ER_TOO_BIG_ROWSIZE
ALTER TABLE t2 DROP p;
SET innodb_strict_mode = OFF;
}
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
--enable_info
ALTER TABLE t2 DROP p;
--disable_info
2019-11-14 13:22:29 +02:00
if ($redundant_4k)
{
SET innodb_strict_mode = ON;
}
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
SELECT * FROM t2;
# datetime
eval CREATE TABLE t3
(id INT PRIMARY KEY, c2 INT UNSIGNED NOT NULL UNIQUE,
c3 POLYGON NOT NULL DEFAULT ST_PolyFromText('POLYGON((1 1,2 2,3 3,1 1))'),
SPATIAL INDEX(c3))
$engine;
INSERT INTO t3(id,c2) VALUES(1,1),(2,2),(3,3);
2017-11-23 15:02:26 +02:00
SELECT id, c2, ST_AsText(c3) c3 FROM t3;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
--enable_info
ALTER TABLE t3 ADD COLUMN
(c4 DATETIME DEFAULT current_timestamp(),
c5 TIMESTAMP NOT NULL DEFAULT current_timestamp(),
c6 POINT);
2017-11-23 15:02:26 +02:00
SELECT id, c2, ST_AsText(c3) c3, c4, c5, c6 FROM t3;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
ALTER TABLE t3 ADD COLUMN c7 TIME NOT NULL DEFAULT current_timestamp();
ALTER TABLE t3 ADD COLUMN c8 DATE NOT NULL DEFAULT current_timestamp();
--disable_info
2017-11-23 15:02:26 +02:00
SELECT id, c2, ST_AsText(c3) c3, c4, c5, c6, c7, c8 FROM t3;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
--enable_info
ALTER TABLE t3 ADD COLUMN t TEXT CHARSET utf8
DEFAULT 'The quick brown fox jumps over the lazy dog';
if ($redundant_4k)
{
--error ER_TOO_BIG_ROWSIZE
ALTER TABLE t3 ADD COLUMN b BLOB NOT NULL;
SET innodb_strict_mode = OFF;
}
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
ALTER TABLE t3 ADD COLUMN b BLOB NOT NULL;
--error ER_NO_DEFAULT_FOR_FIELD
INSERT INTO t3 SET id=4;
INSERT INTO t3 SET id=4, c2=0, b=0xf09f98b1;
2019-07-16 15:42:36 +03:00
SET innodb_strict_mode = OFF;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
ALTER TABLE t3 CHANGE t phrase TEXT DEFAULT 0xc3a4c3a448,
CHANGE b b BLOB NOT NULL DEFAULT 'binary line of business';
--disable_info
INSERT INTO t3 SET id=5, c2=9;
2017-11-23 15:02:26 +02:00
SELECT id, c2, ST_AsText(c3) c3, c4, c5, c6, c7, c8, phrase, b FROM t3;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
--enable_info
ALTER TABLE t3 DROP c3, DROP c7;
--disable_info
SELECT * FROM t3;
eval CREATE TABLE t4
(id INT, foo INT DEFAULT 0, c1 VARCHAR(4000),
p GEOMETRY NOT NULL DEFAULT ST_GeomFromText('LINESTRING(0 0,0 1,1 1)'),
PRIMARY KEY(id,foo))
$engine;
INSERT INTO t4 (id,c1) VALUES (1, REPEAT('a', 4000)), (2, REPEAT('a', 4000));
ALTER TABLE t4 ADD COLUMN d1 INT;
BEGIN;
UPDATE t4 SET c1 = repeat('1', 4000), foo=1 WHERE id=1;
INSERT INTO t4 (id,c1) VALUES (1, REPEAT('a', 4000));
UPDATE t4 SET c1 = repeat('2', 4000), foo=1 WHERE id=2;
ROLLBACK;
BEGIN;
UPDATE t4 SET d1 = 1,foo=2 WHERE id=1;
INSERT INTO t4 (id,foo,c1) VALUES (1, 1, REPEAT('1', 4000));
COMMIT;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
eval CREATE TABLE big
(id INT PRIMARY KEY, c1 VARCHAR(4000), c2 VARCHAR(4000), c3 VARCHAR(1000),
p POINT NOT NULL DEFAULT ST_GeomFromText('POINT(0 0)'), SPATIAL INDEX(p))
$engine;
BEGIN;
INSERT INTO big
SET id=1, c1=REPEAT('a', 200), c2=REPEAT('b', 200), c3=REPEAT('c', 159);
SET @i:=1;
INSERT INTO big SELECT @i:=@i+1, c1, c2, c3, p FROM big;
INSERT INTO big SELECT @i:=@i+1, c1, c2, c3, p FROM big;
INSERT INTO big SELECT @i:=@i+1, c1, c2, c3, p FROM big;
INSERT INTO big SELECT @i:=@i+1, c1, c2, c3, p FROM big;
INSERT INTO big SELECT @i:=@i+1, c1, c2, c3, p FROM big;
COMMIT;
connection analyze;
ANALYZE TABLE big;
SELECT clust_index_size FROM INFORMATION_SCHEMA.INNODB_SYS_TABLESTATS
WHERE name = 'test/big';
connection default;
--enable_info
ALTER TABLE big ADD COLUMN
(d1 INT DEFAULT 0, d2 VARCHAR(20) DEFAULT 'abcde',
d3 TIMESTAMP NOT NULL DEFAULT current_timestamp ON UPDATE current_timestamp);
--disable_info
CHECKSUM TABLE big;
BEGIN;
INSERT INTO big(id, c1, c2, c3) SELECT @i:=@i+1, c1, c2, c3 FROM big;
INSERT INTO big(id, c1, c2, c3) SELECT @i:=@i+1, c1, c2, c3 FROM big;
CHECKSUM TABLE big;
connection analyze;
ANALYZE TABLE big;
SELECT clust_index_size FROM INFORMATION_SCHEMA.INNODB_SYS_TABLESTATS
WHERE name = 'test/big';
connection default;
ROLLBACK;
CHECKSUM TABLE big;
connection analyze;
ANALYZE TABLE big;
SELECT clust_index_size FROM INFORMATION_SCHEMA.INNODB_SYS_TABLESTATS
WHERE name = 'test/big';
connection default;
--source include/wait_all_purged.inc
DROP TABLE t1,t2,t3,t4,big;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
# MDEV-14837 Duplicate primary keys are allowed after ADD COLUMN / UPDATE
eval CREATE TABLE t1 (a VARCHAR(1) PRIMARY KEY) $engine;
INSERT INTO t1 SET a='a';
ALTER TABLE t1 ADD COLUMN b INT NOT NULL DEFAULT 0;
UPDATE t1 SET b = 1;
--error ER_DUP_ENTRY
INSERT INTO t1 SET a='a';
SELECT * FROM t1;
DROP TABLE t1;
# MDEV-16065 Assertion failed in btr_pcur_restore_position_func on UPDATE
eval CREATE TABLE t1 (a INT, b VARCHAR(8), PRIMARY KEY(b,a)) $engine;
INSERT INTO t1 VALUES (1,'foo');
ALTER TABLE t1 ADD COLUMN c INT;
UPDATE t1 SET c = 1;
UPDATE t1 SET c = 2;
DROP TABLE t1;
# MDEV-16830 Crash in ALTER TABLE DROP FOREIGN KEY
eval CREATE TABLE t1 (a INT PRIMARY KEY) $engine;
eval CREATE TABLE t2 (b INT PRIMARY KEY, FOREIGN KEY(b) REFERENCES t1(a))
$engine;
INSERT INTO t1 SET a=1;
INSERT INTO t2 SET b=1;
ALTER TABLE t2 ADD COLUMN a INT, DROP FOREIGN KEY t2_ibfk_1;
ALTER TABLE t2 ADD INDEX(a);
--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
ALTER TABLE t1 ADD COLUMN b INT, ADD FOREIGN KEY(a) REFERENCES t2(a),
ALGORITHM=INSTANT;
SET foreign_key_checks=0;
ALTER TABLE t1 ADD COLUMN b INT, ADD FOREIGN KEY(a) REFERENCES t2(a),
ALGORITHM=INSTANT;
ALTER TABLE t2 ADD CONSTRAINT fk FOREIGN KEY(b) REFERENCES t1(a),
ALGORITHM=INSTANT;
SET foreign_key_checks=1;
ALTER TABLE t2 COMMENT 'domestic keys only', DROP FOREIGN KEY fk;
ALTER TABLE t1 DROP FOREIGN KEY t1_ibfk_1;
ALTER TABLE t1 ADD COLUMN big BLOB NOT NULL
DEFAULT REPEAT('a', @@GLOBAL.innodb_page_size * .75);
CHECK TABLE t2, t1;
DROP TABLE t2, t1;
#
# MDEV-17483 Insert on delete-marked record can wrongly inherit old values
# for instantly added column
#
eval CREATE TABLE t1 (a INT PRIMARY KEY) $engine;
INSERT INTO t1 SET a = 1;
ALTER TABLE t1 ADD COLUMN b TEXT;
BEGIN;
UPDATE t1 SET b = REPEAT('1', 32768);
UPDATE t1 SET a = 2;
INSERT INTO t1 SET a = 1;
SELECT a,LENGTH(b) FROM t1;
DELETE FROM t1;
COMMIT;
--source include/wait_all_purged.inc
DROP TABLE t1;
#
# MDEV-20066 Wrong value on instantly added column after DELETE and UPDATE
#
eval CREATE TABLE t1(a INT PRIMARY KEY) $engine;
INSERT INTO t1 VALUES (7);
ALTER TABLE t1 ADD COLUMN c INT NOT NULL DEFAULT 0;
ALTER TABLE t1 ADD INDEX (c);
BEGIN;
DELETE FROM t1;
INSERT INTO t1 VALUES (4,0),(7,77);
COMMIT;
BEGIN;
DELETE FROM t1 WHERE a=7;
UPDATE t1 SET a=7;
COMMIT;
SELECT * FROM t1 FORCE INDEX(PRIMARY);
SELECT * FROM t1 FORCE INDEX(c);
DELETE FROM t1;
CHECK TABLE t1;
DROP TABLE t1;
# MDEV-21172 Memory leak during ADD PRIMARY KEY
SET innodb_strict_mode = ON;
eval CREATE TABLE t1 (a INT, b VARCHAR(500), c TEXT, UNIQUE(a,b)) $engine;
ALTER TABLE t1 ADD d TEXT;
--error 0,ER_TOO_BIG_ROWSIZE
ALTER TABLE t1 ADD PRIMARY KEY (b,a);
# Exploit MDEV-17468 to force the table definition to be reloaded
ALTER TABLE t1 ADD va INT AS (a) VIRTUAL;
DROP TABLE t1;
SET innodb_strict_mode = OFF;
MDEV-20590 Introduce a file format constraint to ALTER TABLE If a table is altered using the MDEV-11369/MDEV-15562/MDEV-13134 ALGORITHM=INSTANT, it can force the table to use a non-canonical format: * A hidden metadata record at the start of the clustered index is used to store each column's DEFAULT value. This makes it possible to add new columns that have default values without rebuilding the table. * Starting with MDEV-15562 in MariaDB Server 10.4, a BLOB in the hidden metadata record is used to store column mappings. This makes it possible to drop or reorder columns without rebuilding the table. This also makes it possible to add columns to any position or drop columns from any position in the table without rebuilding the table. If a column is dropped without rebuilding the table, old records will contain garbage in that column's former position, and new records will be written with NULL values, empty strings, or dummy values. This is generally not a problem. However, there may be cases where users may want to avoid putting a table into this format. For example, users may want to ensure that future UPDATE operations after an ADD COLUMN will be performed in-place, to reduce write amplification. (Instantly added columns are essentially always variable-length.) Users might also want to avoid bugs similar to MDEV-19916, or they may want to be able to export tables to older versions of the server. We will introduce the option innodb_instant_alter_column_allowed, with the following values: * never (0): Do not allow instant add/drop/reorder, to maintain format compatibility with MariaDB 10.x and MySQL 5.x. If the table (or partition) is not in the canonical format, then any ALTER TABLE (even one that does not involve instant column operations) will force a table rebuild. * add_last (1, default in 10.3): Store a hidden metadata record that allows columns to be appended to the table instantly (MDEV-11369). In 10.4 or later, if the table (or partition) is not in this format, then any ALTER TABLE (even one that does not involve column changes) will force a table rebuild. Starting with 10.4: * add_drop_reorder (2, default): Like 'add_last', but allow the metadata record to store a column map, to support instant add/drop/reorder of columns (MDEV-15562).
2020-03-30 12:31:54 +03:00
# MDEV-20950 innodb_instant_alter_column_allowed
eval CREATE TABLE t1 (a INT PRIMARY KEY) $engine;
INSERT INTO t1 SET a=42;
SET GLOBAL innodb_instant_alter_column_allowed = never;
--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
ALTER TABLE t1 ADD b TEXT, ALGORITHM=INSTANT;
SET GLOBAL innodb_instant_alter_column_allowed = add_last;
ALTER TABLE t1 ADD b TEXT, ALGORITHM=INSTANT;
SET GLOBAL innodb_instant_alter_column_allowed = never;
--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
ALTER TABLE t1 MODIFY a INT DEFAULT 1, ALGORITHM=INSTANT;
--enable_info
ALTER TABLE t1 MODIFY a INT DEFAULT 0;
--disable_info
ALTER TABLE t1 MODIFY a INT DEFAULT NULL, ALGORITHM=INSTANT;
2020-03-30 14:50:23 +03:00
--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
ALTER TABLE t1 DROP b, ALGORITHM=INSTANT;
--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
ALTER TABLE t1 MODIFY b TEXT FIRST, ALGORITHM=INSTANT;
SET GLOBAL innodb_instant_alter_column_allowed = add_last;
--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
ALTER TABLE t1 MODIFY b TEXT FIRST, ALGORITHM=INSTANT;
--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
ALTER TABLE t1 ADD d TEXT AFTER a, ALGORITHM=INSTANT;
SET GLOBAL innodb_instant_alter_column_allowed = add_drop_reorder;
ALTER TABLE t1 MODIFY b TEXT FIRST, ALGORITHM=INSTANT;
MDEV-20590 Introduce a file format constraint to ALTER TABLE If a table is altered using the MDEV-11369/MDEV-15562/MDEV-13134 ALGORITHM=INSTANT, it can force the table to use a non-canonical format: * A hidden metadata record at the start of the clustered index is used to store each column's DEFAULT value. This makes it possible to add new columns that have default values without rebuilding the table. * Starting with MDEV-15562 in MariaDB Server 10.4, a BLOB in the hidden metadata record is used to store column mappings. This makes it possible to drop or reorder columns without rebuilding the table. This also makes it possible to add columns to any position or drop columns from any position in the table without rebuilding the table. If a column is dropped without rebuilding the table, old records will contain garbage in that column's former position, and new records will be written with NULL values, empty strings, or dummy values. This is generally not a problem. However, there may be cases where users may want to avoid putting a table into this format. For example, users may want to ensure that future UPDATE operations after an ADD COLUMN will be performed in-place, to reduce write amplification. (Instantly added columns are essentially always variable-length.) Users might also want to avoid bugs similar to MDEV-19916, or they may want to be able to export tables to older versions of the server. We will introduce the option innodb_instant_alter_column_allowed, with the following values: * never (0): Do not allow instant add/drop/reorder, to maintain format compatibility with MariaDB 10.x and MySQL 5.x. If the table (or partition) is not in the canonical format, then any ALTER TABLE (even one that does not involve instant column operations) will force a table rebuild. * add_last (1, default in 10.3): Store a hidden metadata record that allows columns to be appended to the table instantly (MDEV-11369). In 10.4 or later, if the table (or partition) is not in this format, then any ALTER TABLE (even one that does not involve column changes) will force a table rebuild. Starting with 10.4: * add_drop_reorder (2, default): Like 'add_last', but allow the metadata record to store a column map, to support instant add/drop/reorder of columns (MDEV-15562).
2020-03-30 12:31:54 +03:00
SET GLOBAL innodb_instant_alter_column_allowed = add_last;
2020-03-30 14:50:23 +03:00
--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
ALTER TABLE t1 MODIFY a INT DEFAULT 1, ALGORITHM=INSTANT;
--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
ALTER TABLE t1 ADD d TEXT AFTER a, ALGORITHM=INSTANT;
--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
ALTER TABLE t1 MODIFY a INT DEFAULT 0, ALGORITHM=INSTANT;
--enable_info
ALTER TABLE t1 MODIFY a INT DEFAULT 0;
--disable_info
ALTER TABLE t1 MODIFY a INT DEFAULT NULL, ALGORITHM=INSTANT;
DROP TABLE t1;
SET GLOBAL innodb_instant_alter_column_allowed = DEFAULT;
MDEV-15662 Instant DROP COLUMN or changing the order of columns Allow ADD COLUMN anywhere in a table, not only adding as the last column. Allow instant DROP COLUMN and instant changing the order of columns. The added columns will always be added last in clustered index records. In new records, instantly dropped columns will be stored as NULL or empty when possible. Information about dropped and reordered columns will be written in a metadata BLOB (mblob), which is stored before the first 'user' field in the hidden metadata record at the start of the clustered index. The presence of mblob is indicated by setting the delete-mark flag in the metadata record. The metadata BLOB stores the number of clustered index fields, followed by an array of column information for each field. For dropped columns, we store the NOT NULL flag, the fixed length, and for variable-length columns, whether the maximum length exceeded 255 bytes. For non-dropped columns, we store the column position. Unlike with MDEV-11369, when a table becomes empty, it cannot be converted back to the canonical format. The reason for this is that other threads may hold cached objects such as row_prebuilt_t::ins_node that could refer to dropped or reordered index fields. For instant DROP COLUMN and ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC, we must store the n_core_null_bytes in the root page, so that the chain of node pointer records can be followed in order to reach the leftmost leaf page where the metadata record is located. If the mblob is present, we will zero-initialize the strings "infimum" and "supremum" in the root page, and use the last byte of "supremum" for storing the number of null bytes (which are allocated but useless on node pointer pages). This is necessary for btr_cur_instant_init_metadata() to be able to navigate to the mblob. If the PRIMARY KEY contains any variable-length column and some nullable columns were instantly dropped, the dict_index_t::n_nullable in the data dictionary could be smaller than it actually is in the non-leaf pages. Because of this, the non-leaf pages could use more bytes for the null flags than the data dictionary expects, and we could be reading the lengths of the variable-length columns from the wrong offset, and thus reading the child page number from wrong place. This is the result of two design mistakes that involve unnecessary storage of data: First, it is nonsense to store any data fields for the leftmost node pointer records, because the comparisons would be resolved by the MIN_REC_FLAG alone. Second, there cannot be any null fields in the clustered index node pointer fields, but we nevertheless reserve space for all the null flags. Limitations (future work): MDEV-17459 Allow instant ALTER TABLE even if FULLTEXT INDEX exists MDEV-17468 Avoid table rebuild on operations on generated columns MDEV-17494 Refuse ALGORITHM=INSTANT when the row size is too large btr_page_reorganize_low(): Preserve any metadata in the root page. Call lock_move_reorganize_page() only after restoring the "infimum" and "supremum" records, to avoid a memcmp() assertion failure. dict_col_t::DROPPED: Magic value for dict_col_t::ind. dict_col_t::clear_instant(): Renamed from dict_col_t::remove_instant(). Do not assert that the column was instantly added, because we sometimes call this unconditionally for all columns. Convert an instantly added column to a "core column". The old name remove_instant() could be mistaken to refer to "instant DROP COLUMN". dict_col_t::is_added(): Rename from dict_col_t::is_instant(). dtype_t::metadata_blob_init(): Initialize the mblob data type. dtuple_t::is_metadata(), dtuple_t::is_alter_metadata(), upd_t::is_metadata(), upd_t::is_alter_metadata(): Check if info_bits refer to a metadata record. dict_table_t::instant: Metadata about dropped or reordered columns. dict_table_t::prepare_instant(): Prepare ha_innobase_inplace_ctx::instant_table for instant ALTER TABLE. innobase_instant_try() will pass this to dict_table_t::instant_column(). On rollback, dict_table_t::rollback_instant() will be called. dict_table_t::instant_column(): Renamed from instant_add_column(). Add the parameter col_map so that columns can be reordered. Copy and adjust v_cols[] as well. dict_table_t::find(): Find an old column based on a new column number. dict_table_t::serialise_columns(), dict_table_t::deserialise_columns(): Convert the mblob. dict_index_t::instant_metadata(): Create the metadata record for instant ALTER TABLE. Invoke dict_table_t::serialise_columns(). dict_index_t::reconstruct_fields(): Invoked by dict_table_t::deserialise_columns(). dict_index_t::clear_instant_alter(): Move the fields for the dropped columns to the end, and sort the surviving index fields in ascending order of column position. ha_innobase::check_if_supported_inplace_alter(): Do not allow adding a FTS_DOC_ID column if a hidden FTS_DOC_ID column exists due to FULLTEXT INDEX. (This always required ALGORITHM=COPY.) instant_alter_column_possible(): Add a parameter for InnoDB table, to check for additional conditions, such as the maximum number of index fields. ha_innobase_inplace_ctx::first_alter_pos: The first column whose position is affected by instant ADD, DROP, or changing the order of columns. innobase_build_col_map(): Skip added virtual columns. prepare_inplace_add_virtual(): Correctly compute num_to_add_vcol. Remove some unnecessary code. Note that the call to innodb_base_col_setup() should be executed later. commit_try_norebuild(): If ctx->is_instant(), let the virtual columns be added or dropped by innobase_instant_try(). innobase_instant_try(): Fill in a zero default value for the hidden column FTS_DOC_ID (to reduce the work needed in MDEV-17459). If any columns were dropped or reordered (or added not last), delete any SYS_COLUMNS records for the following columns, and insert SYS_COLUMNS records for all subsequent stored columns as well as for all virtual columns. If any virtual column is dropped, rewrite all virtual column metadata. Use a shortcut only for adding virtual columns. This is because innobase_drop_virtual_try() assumes that the dropped virtual columns still exist in ctx->old_table. innodb_update_cols(): Renamed from innodb_update_n_cols(). innobase_add_one_virtual(), innobase_insert_sys_virtual(): Change the return type to bool, and invoke my_error() when detecting an error. innodb_insert_sys_columns(): Insert a record into SYS_COLUMNS. Refactored from innobase_add_one_virtual() and innobase_instant_add_col(). innobase_instant_add_col(): Replace the parameter dfield with type. innobase_instant_drop_cols(): Drop matching columns from SYS_COLUMNS and all columns from SYS_VIRTUAL. innobase_add_virtual_try(), innobase_drop_virtual_try(): Let the caller invoke innodb_update_cols(). innobase_rename_column_try(): Skip dropped columns. commit_cache_norebuild(): Update table->fts->doc_col. dict_mem_table_col_rename_low(): Skip dropped columns. trx_undo_rec_get_partial_row(): Skip dropped columns. trx_undo_update_rec_get_update(): Handle the metadata BLOB correctly. trx_undo_page_report_modify(): Avoid out-of-bounds access to record fields. Log metadata records consistently. Apparently, the first fields of a clustered index may be updated in an update_undo vector when the index is ID_IND of SYS_FOREIGN, as part of renaming the table during ALTER TABLE. Normally, updates of the PRIMARY KEY should be logged as delete-mark and an insert. row_undo_mod_parse_undo_rec(), row_purge_parse_undo_rec(): Use trx_undo_metadata. row_undo_mod_clust_low(): On metadata rollback, roll back the root page too. row_undo_mod_clust(): Relax an assertion. The delete-mark flag was repurposed for ALTER TABLE metadata records. row_rec_to_index_entry_impl(): Add the template parameter mblob and the optional parameter info_bits for specifying the desired new info bits. For the metadata tuple, allow conversion between the original format (ADD COLUMN only) and the generic format (with hidden BLOB). Add the optional parameter "pad" to determine whether the tuple should be padded to the index fields (on ALTER TABLE it should), or whether it should remain at its original size (on rollback). row_build_index_entry_low(): Clean up the code, removing redundant variables and conditions. For instantly dropped columns, generate a dummy value that is NULL, the empty string, or a fixed length of NUL bytes, depending on the type of the dropped column. row_upd_clust_rec_by_insert_inherit_func(): On the update of PRIMARY KEY of a record that contained a dropped column whose value was stored externally, we will be inserting a dummy NULL or empty string value to the field of the dropped column. The externally stored column would eventually be dropped when purge removes the delete-marked record for the old PRIMARY KEY value. btr_index_rec_validate(): Recognize the metadata record. btr_discard_only_page_on_level(): Preserve the generic instant ALTER TABLE metadata. btr_set_instant(): Replaces page_set_instant(). This sets a clustered index root page to the appropriate format, or upgrades from the MDEV-11369 instant ADD COLUMN to generic ALTER TABLE format. btr_cur_instant_init_low(): Read and validate the metadata BLOB page before reconstructing the dictionary information based on it. btr_cur_instant_init_metadata(): Do not read any lengths from the metadata record header before reading the BLOB. At this point, we would not actually know how many nullable fields the metadata record contains. btr_cur_instant_root_init(): Initialize n_core_null_bytes in one of two possible ways. btr_cur_trim(): Handle the mblob record. row_metadata_to_tuple(): Convert a metadata record to a data tuple, based on the new info_bits of the metadata record. btr_cur_pessimistic_update(): Invoke row_metadata_to_tuple() if needed. Invoke dtuple_convert_big_rec() for metadata records if the record is too large, or if the mblob is not yet marked as externally stored. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): When the last user record is deleted, do not delete the generic instant ALTER TABLE metadata record. Only delete MDEV-11369 instant ADD COLUMN metadata records. btr_cur_optimistic_insert(): Avoid unnecessary computation of rec_size. btr_pcur_store_position(): Allow a logically empty page to contain a metadata record for generic ALTER TABLE. REC_INFO_DEFAULT_ROW_ADD: Renamed from REC_INFO_DEFAULT_ROW. This is for the old instant ADD COLUMN (MDEV-11369) only. REC_INFO_DEFAULT_ROW_ALTER: The more generic metadata record, with additional information for dropped or reordered columns. rec_info_bits_valid(): Remove. The only case when this would fail is when the record is the generic ALTER TABLE metadata record. rec_is_alter_metadata(): Check if a record is the metadata record for instant ALTER TABLE (other than ADD COLUMN). NOTE: This function must not be invoked on node pointer records, because the delete-mark flag in those records may be set (it is garbage), and then a debug assertion could fail because index->is_instant() does not necessarily hold. rec_is_add_metadata(): Check if a record is MDEV-11369 ADD COLUMN metadata record (not more generic instant ALTER TABLE). rec_get_converted_size_comp_prefix_low(): Assume that the metadata field will be stored externally. In dtuple_convert_big_rec() during the rec_get_converted_size() call, it would not be there yet. rec_get_converted_size_comp(): Replace status,fields,n_fields with tuple. rec_init_offsets_comp_ordinary(), rec_get_converted_size_comp_prefix_low(), rec_convert_dtuple_to_rec_comp(): Add template<bool mblob = false>. With mblob=true, process a record with a metadata BLOB. rec_copy_prefix_to_buf(): Assert that no fields beyond the key and system columns are being copied. Exclude the metadata BLOB field. rec_convert_dtuple_to_metadata_comp(): Convert an alter metadata tuple into a record. row_upd_index_replace_metadata(): Apply an update vector to an alter_metadata tuple. row_log_allocate(): Replace dict_index_t::is_instant() with a more appropriate condition that ignores dict_table_t::instant. Only a table on which the MDEV-11369 ADD COLUMN was performed can "lose its instantness" when it becomes empty. After instant DROP COLUMN or reordering columns, we cannot simply convert the table to the canonical format, because the data dictionary cache and all possibly existing references to it from other client connection threads would have to be adjusted. row_quiesce_write_index_fields(): Do not crash when the table contains an instantly dropped column. Thanks to Thirunarayanan Balathandayuthapani for discussing the design and implementing an initial prototype of this. Thanks to Matthias Leich for testing.
2018-10-19 16:49:54 +03:00
# MDEV-15562 Instant DROP/ADD/reorder columns
eval CREATE TABLE t1 (a INT, b INT UNIQUE) $engine;
INSERT INTO t1 (a) VALUES (NULL), (NULL);
ALTER TABLE t1 DROP a, ADD COLUMN a INT;
DELETE FROM t1;
BEGIN;INSERT INTO t1 SET a=NULL;ROLLBACK;
DELETE FROM t1;
DROP TABLE t1;
eval CREATE TABLE t1 (a INT PRIMARY KEY, t VARCHAR(33101) NOT NULL) $engine;
INSERT INTO t1 VALUES(347,'');
ALTER TABLE t1 DROP COLUMN t, ALGORITHM=INSTANT;
SELECT * FROM t1;
DROP TABLE t1;
eval CREATE TABLE t1 (a INT) $engine;
INSERT INTO t1() VALUES();
ALTER TABLE t1 ADD COLUMN b INT FIRST, ADD COLUMN c INT AFTER b;
SELECT * FROM t1;
DROP TABLE t1;
eval CREATE TABLE t1 (t TEXT) $engine;
SET @t=REPEAT('x',@@innodb_page_size / 2);
INSERT INTO t1 VALUES (@t),(@t),(@t),(@t),(@t),(@t),(NULL),(@t),(@t),(@t),(@t);
ALTER TABLE t1 ADD COLUMN a INT FIRST;
UPDATE t1 SET a = 0;
DROP TABLE t1;
eval CREATE TABLE t1 (t TEXT) $engine;
INSERT INTO t1 SET t = @x;
ALTER TABLE t1 DROP COLUMN t, ADD COLUMN i INT NOT NULL DEFAULT 1;
ALTER TABLE t1 ADD COLUMN t TEXT;
SELECT * FROM t1;
DROP TABLE t1;
#
# MDEV-17735 Assertion failure in row_parse_int() on first ADD/DROP COLUMN
# when an AUTO_INCREMENT column is not in PRIMARY KEY
#
eval CREATE TABLE t1 (a INT AUTO_INCREMENT, b INT, KEY(a)) $engine;
INSERT INTO t1 SET a=NULL;
ALTER TABLE t1 DROP COLUMN b;
ALTER TABLE t1 ADD COLUMN c INT NOT NULL DEFAULT 42;
INSERT INTO t1 SET a=NULL;
UPDATE t1 SET a=a+2;
SELECT * FROM t1;
DROP TABLE t1;
eval CREATE TABLE t1 (i INT) $engine;
INSERT INTO t1 SET i=1;
ALTER TABLE t1 ADD COLUMN b BIT FIRST;
ALTER TABLE t1 ADD COLUMN v INT AS (i) VIRTUAL;
SELECT * FROM t1;
DROP TABLE t1;
# MDEV-17721 Corrupted data dictionary after instant DROP COLUMN
eval CREATE TABLE t1 (ts TIMESTAMP) $engine;
ALTER TABLE t1 ADD COLUMN f VARCHAR(8), ADD COLUMN dt DATETIME;
ALTER TABLE t1 ADD COLUMN b BIT, DROP COLUMN f, ADD COLUMN t TIME FIRST;
ALTER TABLE t1 ADD COLUMN ts2 TIMESTAMP;
DROP TABLE t1;
eval CREATE TABLE t1 (f1 INT, f2 INT, f3 INT) $engine;
INSERT INTO t1 VALUES (4,4,4);
ALTER TABLE t1 DROP f1, DROP f2, ADD f4 INT, ADD f5 INT;
DELETE FROM t1;
ALTER TABLE t1 DROP COLUMN f4;
DROP TABLE t1;
eval CREATE TABLE t1 (f1 INT, f2 INT, f3 INT) $engine;
ALTER TABLE t1 DROP f2, ADD COLUMN f4 INT;
ALTER TABLE t1 DROP f4;
ALTER TABLE t1 DROP f1;
DROP TABLE t1;
# MDEV-17901 Crash after instant DROP COLUMN of AUTO_INCREMENT column
eval CREATE TABLE t1 (id INT NOT NULL AUTO_INCREMENT, f INT, KEY(id)) $engine;
ALTER TABLE t1 DROP COLUMN id;
INSERT INTO t1 () VALUES (),();
SELECT * FROM t1;
# Adding AUTO_INCREMENT column will always require rebuild.
ALTER TABLE t1 ADD COLUMN id INT NOT NULL AUTO_INCREMENT FIRST, ADD KEY(id);
SELECT * FROM t1;
DROP TABLE t1;
# MDEV-18149 Crash after DROP COLUMN of AUTO_INCREMENT column on nonempty table
eval CREATE TABLE t1 (id INT NOT NULL AUTO_INCREMENT, f INT, KEY(id)) $engine;
INSERT INTO t1 SET f=NULL;
ALTER TABLE t1 DROP COLUMN id;
INSERT INTO t1 SET f=NULL;
SELECT * FROM t1;
DROP TABLE t1;
# MDEV-18076/MDEV-18077 Crash on AUTO_INCREMENT column after instant DROP
eval CREATE TABLE t1(f INT, k INT NOT NULL AUTO_INCREMENT, KEY(k)) $engine;
ALTER TABLE t1 DROP COLUMN f;
INSERT INTO t1 VALUES (1);
DROP TABLE t1;
eval CREATE TABLE t1(pk INT PRIMARY KEY, f INT, k INT AUTO_INCREMENT, KEY(k))
$engine;
ALTER TABLE t1 DROP COLUMN f;
INSERT INTO t1 (pk) VALUES (1);
DROP TABLE t1;
# MDEV-17763 Assertion `len == 20U' failed in rec_convert_dtuple_to_rec_comp
# upon DROP COLUMN
eval CREATE TABLE t1 (
pk INT PRIMARY KEY,
f1 INT,
f2 CHAR(255),
f3 BIGINT,
f4 INT,
f5 CHAR(255),
f6 CHAR(255),
f7 CHAR(255) NOT NULL,
f8 INT,
f9 CHAR(10)
) $engine;
INSERT INTO t1 VALUES
(1, 1, 'a', 1, 1, 'a', 'a', 'a', 1, 'a'),
(2, 2, 'b', 2, 2, 'b', 'b', 'b', 2, 'b'),
(3, 3, 'c', 3, 3, 'c', 'c', 'c', 3, 'c'),
(4, 4, 'd', 4, 4, 'd', 'd', 'd', 4, 'd'),
(5, 5, 'e', 5, 5, 'e', 'e', 'e', 5, 'e'),
(6, 6, 'f', 6, 6, 'f', 'f', 'f', 6, 'f'),
(7, 7, 'g', 7, 7, 'g', 'g', 'g', 7, 'g'),
(8, 8, 'h', 8, 8, 'h', 'h', 'h', 8, 'h'),
(9, 9, 'i', 9, 9, 'i', 'i', 'i', 9, 'i'),
(10, 0, 'j', 0, 0, 'j', 'j', 'j', 0, 'j'),
(11, 1, 'k', 1, 1, 'k', 'k', 'k', 1, 'k'),
(12, 2, 'l', 2, 2, 'l', 'l', 'l', 2, 'l'),
(13, 3, 'm', 3, 3, 'm', 'm', 'm', 3, 'm'),
(14, 4, 'n', 4, 4, 'n', 'n', 'n', 4, 'n'),
(15, 5, 'o', 5, 5, 'o', 'o', 'o', 5, 'o');
DELETE FROM t1 WHERE pk=1;
--source include/wait_all_purged.inc
INSERT INTO t1 VALUES
(1, 1, 'a', 1, 1, 'a', 'a', 'a', 1, 'a');
ALTER TABLE t1 DROP COLUMN f1;
DROP TABLE t1;
# MDEV-17820 Assertion failures on DROP COLUMN
eval CREATE TABLE t1 (
pk INT PRIMARY KEY,
f1 INT, f2 CHAR(32) NOT NULL,
f3 INT NOT NULL, f4 INT NOT NULL, f5 INT, f6 CHAR(32) NOT NULL,
f7 CHAR(32), f8 CHAR(32)
) $engine;
INSERT INTO t1 VALUES
(1,9,'',2,88,88,'','',''),(2,48,'',8,68,92,'','',''),
(3,41,'',56,84,37,'','',''),(4,NULL,'',6,6,NULL,'','',''),
(5,52,'',37,44,20,'','',''),(6,44,'',53,4,NULL,'','',''),
(7,24,'',54,8,54,'','',''),(8,80,'',3,52,20,'','',''),
(9,71,'',34,32,NULL,'','',''),(10,14,'',6,64,88,'','',''),
(11,48,'',8,25,42,'','',''),(12,16,'',8,7,NULL,'','',''),
(13,NULL,'',22,0,95,'','',''),(14,4,'',72,48,NULL,'','',''),
(15,4,'',5,64,2,'','',''),(16,NULL,'',9,40,30,'','',''),
(17,92,'',48,2,NULL,'','',''),(18,36,'',48,51,7,'','',''),
(19,NULL,'',80,96,NULL,'','',''),(20,96,'',9,80,NULL,'','',''),
(21,50,'',16,40,NULL,'','',''),(22,NULL,'',7,84,8,'','',''),
(23,28,'',93,80,NULL,'','',''),(24,31,'',40,38,NULL,'','',''),
(25,85,'',8,5,88,'','',''),(26,66,'',8,32,4,'','',''),
(51,52,'',6,92,15,'','',''),(52,77,'',24,24,28,'','',''),
(53,8,'',75,31,NULL,'','',''),(54,48,'',5,8,1,'','',''),
(55,90,'',56,12,5,'','',''),(56,92,'',4,9,88,'','',''),
(57,83,'',23,40,72,'','',''),(58,7,'',4,40,32,'','',''),
(59,28,'',2,3,32,'','',''),(60,16,'',80,4,NULL,'','',''),
(61,44,'',88,24,NULL,'','',''),(62,4,'',5,25,3,'','',''),
(63,NULL,'',7,24,76,'','',''),(64,0,'',13,40,73,'','',''),
(101,NULL,'',1,49,75,'','',''),(102,34,'',10,17,20,'','',''),
(103,8,'',2,2,NULL,'','',''),(104,12,'',44,48,52,'','',''),
(105,8,'',4,19,38,'','',''),(106,20,'',6,80,9,'','',''),
(107,72,'',72,16,56,'','',''),(108,76,'',98,24,21,'','',''),
(109,67,'',16,91,NULL,'','',''),(110,72,'',72,3,48,'','',''),
(151,8,'',3,86,NULL,'','',''),(152,NULL,'',52,72,0,'','',''),
(153,NULL,'',46,30,92,'','',''),(154,80,'',1,40,48,'','',''),
(155,24,'',68,68,8,'','',''),(156,85,'',85,72,60,'','',''),
(157,7,'',7,12,6,'','',''),(158,NULL,'',48,48,80,'','',''),
(159,12,'',0,36,0,'','',''),(160,2,'',6,52,NULL,'','',''),
(201,0,'',1,3,NULL,'','',''),(202,NULL,'',3,53,14,'','',''),
(203,84,'',6,20,NULL,'','',''),(204,38,'',25,13,88,'','',''),
(205,1,'',2,69,5,'','',''),(206,7,'',60,22,NULL,'','',''),
(207,NULL,'',5,4,NULL,'','',''),(251,7,'',0,4,40,'','',''),
(252,4,'',16,8,NULL,'','',''),(253,14,'',60,12,99,'','',''),
(254,84,'',68,16,5,'','',''),(255,3,'',70,36,61,'','',''),
(256,7,'',18,48,NULL,'','',''),(257,NULL,'',68,53,NULL,'','',''),
(258,29,'',52,16,64,'','',''),(259,NULL,'',80,92,40,'','',''),
(301,68,'',1,48,48,'','',''),(302,2,'',1,1,32,'','',''),
(303,44,'',60,96,16,'','',''),(304,32,'',52,64,32,'','',''),
(305,88,'',37,72,NULL,'','',''),(306,5,'',35,60,20,'','',''),
(307,35,'',4,48,NULL,'','',''),(308,4,'',92,44,80,'','',''),
(351,48,'',60,4,40,'','',''),(352,7,'',9,61,13,'','',''),
(353,0,'',5,93,53,'','',''),(354,7,'',1,20,NULL,'','',''),
(355,84,'',5,48,96,'','',''),(356,NULL,'',39,92,36,'','',''),
(357,88,'',9,76,44,'','',''),(358,66,'',34,67,80,'','',''),
(359,8,'',8,52,NULL,'','',''),(360,3,'',53,83,NULL,'','',''),
(361,23,'',44,9,48,'','',''),(362,4,'',0,54,48,'','',''),
(363,75,'',66,76,52,'','','');
ALTER TABLE t1 ADD COLUMN x VARCHAR(255) DEFAULT ' foobar ';
UPDATE t1 SET f1 = 0;
ALTER TABLE t1 DROP COLUMN x;
DROP TABLE t1;
eval CREATE TABLE t1 (f1 VARCHAR(1), f2 VARCHAR(2)) $engine;
ALTER TABLE t1 MODIFY f2 VARCHAR (8) FIRST;
DROP TABLE t1;
# MDEV-18035 Failing assertion on DELETE
eval CREATE TABLE t1 (a INT UNIQUE, b INT UNIQUE, PRIMARY KEY(a,b)) $engine;
ALTER TABLE t1 DROP PRIMARY KEY;
ALTER TABLE t1 CHANGE COLUMN a a INT;
DELETE FROM t1 WHERE a = NULL OR a IS NULL;
DROP TABLE t1;
# MDEV-18048 Failing assertion on ALTER
eval CREATE TABLE t1 (a INT, b INT, c INT NOT NULL, d INT,
e INT, f INT, g INT, h INT, j INT) $engine;
ALTER TABLE t1 MODIFY COLUMN c INT, MODIFY COLUMN a INT AFTER b;
DROP TABLE t1;
# MDEV-18649 Failing assertion on ALTER for ROW_FORMAT=REDUNDANT
eval CREATE TABLE t1 (a INT NOT NULL, b INT NOT NULL) $engine;
INSERT INTO t1 VALUES (0,0);
ALTER TABLE t1 MODIFY a INT AFTER b;
# Exploit MDEV-17468 to force the table definition to be reloaded
ALTER TABLE t1 ADD COLUMN v INT AS (a) VIRTUAL;
ALTER TABLE t1 MODIFY b INT NOT NULL AFTER a;
DROP TABLE t1;
# MDEV-18033/MDEV-18034 Failing assertion on ALTER
eval CREATE TABLE t1 (a INT NOT NULL) $engine;
INSERT INTO t1 VALUES (1);
ALTER TABLE t1 ADD COLUMN b INT;
ALTER TABLE t1 MODIFY COLUMN a INT NULL;
DROP TABLE t1;
# MDEV-18160/MDEV-18162 Failing assertion on ALTER
eval CREATE TABLE t1 (a INT PRIMARY KEY, b INT, c INT) $engine;
INSERT INTO t1 SET a=1;
ALTER TABLE t1 DROP c;
ALTER TABLE t1 DROP b, ADD v INT AS (a);
DROP TABLE t1;
eval CREATE TABLE t1 (a INT PRIMARY KEY, b INT, c INT, d INT) $engine;
INSERT INTO t1 SET a=1;
ALTER TABLE t1 DROP c;
ALTER TABLE t1 DROP b, ADD v INT AS (a);
DROP TABLE t1;
# MDEV-18218 Assertion `0' failed in btr_page_reorganize_low upon DROP COLUMN
eval CREATE TABLE t1 (pk INT PRIMARY KEY, i INT, b BLOB NOT NULL) $engine;
INSERT INTO t1 VALUES (1,10,REPEAT('foobar',2000));
ALTER TABLE t1 DROP COLUMN b;
INSERT INTO t1 VALUES (2,20);
# this evicts and reloads the table definition until MDEV-17468 is fixed
ALTER TABLE t1 ADD COLUMN vpk INT AS (pk);
# this would load wrong metadata from the previous DROP COLUMN b, causing a crash
ALTER TABLE t1 DROP COLUMN i;
DROP TABLE t1;
# MDEV-18315 Assertion instant.fields[i].col->same_format(*fields[i].col)
# failed in dict_index_t::instant_add_field
eval CREATE TABLE t1 (a INT, b INT) $engine;
INSERT INTO t1 VALUES (1,1);
ALTER TABLE t1 ADD f DATE AFTER a;
ALTER TABLE t1 DROP b, DROP f;
DROP TABLE t1;
# MDEV-18316 Assertion is_added() failed in dict_col_t::instant_value
eval CREATE TABLE t1 (a INT, b INT) $engine;
INSERT INTO t1 VALUES (1,1);
ALTER TABLE t1 ADD COLUMN f INT AFTER a;
ALTER TABLE t1 DROP b, DROP f;
DROP TABLE t1;
# MDEV-18579 Assertion !ctx->online || num_fts_index == 0
eval CREATE TABLE t1(t TEXT NOT NULL, FULLTEXT(t)) $engine;
ALTER TABLE t1 MODIFY COLUMN t TEXT;
DROP TABLE t1;
# MDEV-18598 Assertions and wrong results after MDEV-15563 extending INT
eval CREATE TABLE t1 (f TINYINT, g SMALLINT UNSIGNED) $engine;
INSERT INTO t1 VALUES(127,6502),(-128,33101);
--enable_info
ALTER TABLE t1 MODIFY f SMALLINT DEFAULT 12345,
MODIFY g BIGINT UNSIGNED DEFAULT 1234567;
--disable_info
SELECT * FROM t1;
DROP TABLE t1;
eval CREATE TABLE t1 (f BIT(8)) $engine;
INSERT INTO t1 VALUES (b'10000000'),(b'00000001');
--enable_info
ALTER TABLE t1 MODIFY f BIT(16);
--disable_info
INSERT INTO t1 VALUES (b'1000000010101111'),(b'10000000');
SELECT HEX(f) FROM t1;
--error ER_WARN_DATA_OUT_OF_RANGE
ALTER TABLE t1 MODIFY f SMALLINT;
--enable_info
ALTER TABLE t1 MODIFY f SMALLINT UNSIGNED;
--disable_info
SELECT * FROM t1;
--error ER_DATA_TOO_LONG
ALTER TABLE t1 MODIFY f BIT;
--error ER_DATA_TOO_LONG
ALTER TABLE t1 MODIFY f BIT(15);
DELETE FROM t1 LIMIT 3;
--enable_info
ALTER TABLE t1 MODIFY f BIT(15);
ALTER TABLE t1 MODIFY f BIT(8);
--disable_info
SELECT HEX(f) FROM t1;
DROP TABLE t1;
eval CREATE TABLE t1 (b BIT NOT NULL) $engine DEFAULT CHARSET utf16;
INSERT INTO t1 SET b=b'1';
--enable_info
ALTER TABLE t1 CHANGE b c BIT NOT NULL;
--disable_info
SELECT HEX(c) FROM t1;
DROP TABLE t1;
eval CREATE TABLE t1 (c VARCHAR(10) NOT NULL DEFAULT 'scary') $engine;
INSERT INTO t1() VALUES();
--enable_info
ALTER TABLE t1 ADD f TINYINT NOT NULL DEFAULT -42;
ALTER TABLE t1 MODIFY f MEDIUMINT NOT NULL DEFAULT 64802,
MODIFY c VARCHAR(20) NOT NULL DEFAULT 'gory',
ADD d DATETIME;
--disable_info
INSERT INTO t1() VALUES();
INSERT INTO t1 (c,f,d) VALUES ('fury', -8388608, now());
SELECT * FROM t1;
DROP TABLE t1;
eval CREATE TABLE t1 (t TINYINT PRIMARY KEY, m MEDIUMINT UNIQUE) $engine;
--disable_cursor_protocol
SELECT table_id INTO @table_id1 FROM INFORMATION_SCHEMA.INNODB_SYS_TABLESTATS
WHERE name = 'test/t1';
--enable_cursor_protocol
INSERT INTO t1 VALUES (-42, -123456);
--enable_info
ALTER TABLE t1 CHANGE t s SMALLINT;
--disable_cursor_protocol
SELECT table_id INTO @table_id2 FROM INFORMATION_SCHEMA.INNODB_SYS_TABLESTATS
WHERE name = 'test/t1';
--enable_cursor_protocol
--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
ALTER TABLE t1 CHANGE m i INT, ALGORITHM=INSTANT;
ALTER TABLE t1 CHANGE m i INT;
--disable_cursor_protocol
SELECT table_id INTO @table_id3 FROM INFORMATION_SCHEMA.INNODB_SYS_TABLESTATS
WHERE name = 'test/t1';
--enable_cursor_protocol
--disable_info
SELECT @table_id1 = @table_id2, @table_id2 = @table_id3;
INSERT IGNORE INTO t1 VALUES (0, -123456);
REPLACE INTO t1 VALUES(-42, 123456);
INSERT IGNORE INTO t1 VALUES(32768, 2147483648);
SELECT * FROM t1;
DROP TABLE t1;
eval CREATE TABLE t1 (a SERIAL, b INT, c TINYINT UNIQUE) $engine;
INSERT INTO t1 (c) VALUES(1),(2),(3);
--enable_info
ALTER TABLE t1 MODIFY c BIGINT;
--disable_info
UPDATE t1 SET b=1 WHERE c=2;
UPDATE t1 SET c=4 WHERE a=3;
UPDATE t1 SET b=2 WHERE c>3;
--error ER_DUP_ENTRY
UPDATE t1 SET c=c+1;
SELECT * FROM t1;
DROP TABLE t1;
# MDEV-18719 Assertion (c.prtype ^ o->prtype) & ... failed on ALTER TABLE
eval CREATE TABLE t1 (a INT PRIMARY KEY, b VARCHAR(1)) $engine;
INSERT INTO t1 VALUES(1,'a');
ALTER TABLE t1 MODIFY b VARCHAR(256), ADD COLUMN c INT;
INSERT INTO t1 VALUES(2,'bah',3);
SELECT * FROM t1;
DROP TABLE t1;
# MDEV-21088 Table cannot be loaded after instant ADD/DROP COLUMN
eval CREATE TABLE t1(a CHAR(5) CHARACTER SET utf8 PRIMARY KEY) $engine;
INSERT INTO t1 VALUES('barf');
ALTER TABLE t1 ADD b INT FIRST, ALGORITHM=INSTANT;
# this evicts and reloads the table definition until MDEV-17468 is fixed
ALTER TABLE t1 ADD vb INT AS (b);
SELECT * FROM t1;
DROP TABLE t1;
# MDEV-21148 Assertion failure index->n_core_fields + n_add >= index->n_fields
eval CREATE TABLE t1 (a INT, b TEXT, PRIMARY KEY(b(9))) $engine;
ALTER TABLE t1 ADD COLUMN c TEXT FIRST;
ALTER TABLE t1 ADD COLUMN d TEXT GENERATED ALWAYS AS (SUBSTR(b,1,499)) FIRST;
DROP TABLE t1;
eval CREATE TABLE t1(a CHAR(5), b INT, c CHAR(1), d CHAR(1), PRIMARY KEY(a,b))
DEFAULT CHARACTER SET utf8 $engine;
INSERT INTO t1 SET a='fubar',b=42;
ALTER TABLE t1 DROP c, DROP d, ALGORITHM=INSTANT;
# this evicts and reloads the table definition until MDEV-17468 is fixed
ALTER TABLE t1 ADD vb INT AS (b);
SELECT * FROM t1;
DROP TABLE t1;
eval CREATE TABLE t1 (a INT, b INT, PRIMARY KEY(a,b)) $engine;
ALTER TABLE t1 MODIFY b INT FIRST;
DROP TABLE t1;
# MDEV-21744 Assertion `!rec_offs_nth_sql_null(offsets, n)' failed
eval CREATE TABLE t1 (pk INT PRIMARY KEY) $engine;
INSERT INTO t1 SET pk=1;
ALTER TABLE t1 ADD COLUMN b INT;
BEGIN;
UPDATE t1 SET pk=2;
UPDATE t1 SET pk=1;
connection analyze;
SELECT * FROM t1;
connection default;
DROP TABLE t1;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
dec $format;
let $redundant_4k= 0;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
}
disconnect analyze;
--echo #
--echo # MDEV-22465: DROP COLUMN is wrongly claimed to be ALGORITHM=INSTANT
--echo #
CREATE TABLE t1(a INT PRIMARY KEY, b INT UNIQUE) ENGINE=InnoDB;
--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
ALTER TABLE t1 DROP b, ALGORITHM=INSTANT;
ALTER TABLE t1 DROP b, ALGORITHM=NOCOPY;
DROP TABLE t1;
MDEV-11369 Instant ADD COLUMN for InnoDB For InnoDB tables, adding, dropping and reordering columns has required a rebuild of the table and all its indexes. Since MySQL 5.6 (and MariaDB 10.0) this has been supported online (LOCK=NONE), allowing concurrent modification of the tables. This work revises the InnoDB ROW_FORMAT=REDUNDANT, ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC so that columns can be appended instantaneously, with only minor changes performed to the table structure. The counter innodb_instant_alter_column in INFORMATION_SCHEMA.GLOBAL_STATUS is incremented whenever a table rebuild operation is converted into an instant ADD COLUMN operation. ROW_FORMAT=COMPRESSED tables will not support instant ADD COLUMN. Some usability limitations will be addressed in subsequent work: MDEV-13134 Introduce ALTER TABLE attributes ALGORITHM=NOCOPY and ALGORITHM=INSTANT MDEV-14016 Allow instant ADD COLUMN, ADD INDEX, LOCK=NONE The format of the clustered index (PRIMARY KEY) is changed as follows: (1) The FIL_PAGE_TYPE of the root page will be FIL_PAGE_TYPE_INSTANT, and a new field PAGE_INSTANT will contain the original number of fields in the clustered index ('core' fields). If instant ADD COLUMN has not been used or the table becomes empty, or the very first instant ADD COLUMN operation is rolled back, the fields PAGE_INSTANT and FIL_PAGE_TYPE will be reset to 0 and FIL_PAGE_INDEX. (2) A special 'default row' record is inserted into the leftmost leaf, between the page infimum and the first user record. This record is distinguished by the REC_INFO_MIN_REC_FLAG, and it is otherwise in the same format as records that contain values for the instantly added columns. This 'default row' always has the same number of fields as the clustered index according to the table definition. The values of 'core' fields are to be ignored. For other fields, the 'default row' will contain the default values as they were during the ALTER TABLE statement. (If the column default values are changed later, those values will only be stored in the .frm file. The 'default row' will contain the original evaluated values, which must be the same for every row.) The 'default row' must be completely hidden from higher-level access routines. Assertions have been added to ensure that no 'default row' is ever present in the adaptive hash index or in locked records. The 'default row' is never delete-marked. (3) In clustered index leaf page records, the number of fields must reside between the number of 'core' fields (dict_index_t::n_core_fields introduced in this work) and dict_index_t::n_fields. If the number of fields is less than dict_index_t::n_fields, the missing fields are replaced with the column value of the 'default row'. Note: The number of fields in the record may shrink if some of the last instantly added columns are updated to the value that is in the 'default row'. The function btr_cur_trim() implements this 'compression' on update and rollback; dtuple::trim() implements it on insert. (4) In ROW_FORMAT=COMPACT and ROW_FORMAT=DYNAMIC records, the new status value REC_STATUS_COLUMNS_ADDED will indicate the presence of a new record header that will encode n_fields-n_core_fields-1 in 1 or 2 bytes. (In ROW_FORMAT=REDUNDANT records, the record header always explicitly encodes the number of fields.) We introduce the undo log record type TRX_UNDO_INSERT_DEFAULT for covering the insert of the 'default row' record when instant ADD COLUMN is used for the first time. Subsequent instant ADD COLUMN can use TRX_UNDO_UPD_EXIST_REC. This is joint work with Vin Chen (陈福荣) from Tencent. The design that was discussed in April 2017 would not have allowed import or export of data files, because instead of the 'default row' it would have introduced a data dictionary table. The test rpl.rpl_alter_instant is exactly as contributed in pull request #408. The test innodb.instant_alter is based on a contributed test. The redo log record format changes for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT are as contributed. (With this change present, crash recovery from MariaDB 10.3.1 will fail in spectacular ways!) Also the semantics of higher-level redo log records that modify the PAGE_INSTANT field is changed. The redo log format version identifier was already changed to LOG_HEADER_FORMAT_CURRENT=103 in MariaDB 10.3.1. Everything else has been rewritten by me. Thanks to Elena Stepanova, the code has been tested extensively. When rolling back an instant ADD COLUMN operation, we must empty the PAGE_FREE list after deleting or shortening the 'default row' record, by calling either btr_page_empty() or btr_page_reorganize(). We must know the size of each entry in the PAGE_FREE list. If rollback left a freed copy of the 'default row' in the PAGE_FREE list, we would be unable to determine its size (if it is in ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC) because it would contain more fields than the rolled-back definition of the clustered index. UNIV_SQL_DEFAULT: A new special constant that designates an instantly added column that is not present in the clustered index record. len_is_stored(): Check if a length is an actual length. There are two magic length values: UNIV_SQL_DEFAULT, UNIV_SQL_NULL. dict_col_t::def_val: The 'default row' value of the column. If the column is not added instantly, def_val.len will be UNIV_SQL_DEFAULT. dict_col_t: Add the accessors is_virtual(), is_nullable(), is_instant(), instant_value(). dict_col_t::remove_instant(): Remove the 'instant ADD' status of a column. dict_col_t::name(const dict_table_t& table): Replaces dict_table_get_col_name(). dict_index_t::n_core_fields: The original number of fields. For secondary indexes and if instant ADD COLUMN has not been used, this will be equal to dict_index_t::n_fields. dict_index_t::n_core_null_bytes: Number of bytes needed to represent the null flags; usually equal to UT_BITS_IN_BYTES(n_nullable). dict_index_t::NO_CORE_NULL_BYTES: Magic value signalling that n_core_null_bytes was not initialized yet from the clustered index root page. dict_index_t: Add the accessors is_instant(), is_clust(), get_n_nullable(), instant_field_value(). dict_index_t::instant_add_field(): Adjust clustered index metadata for instant ADD COLUMN. dict_index_t::remove_instant(): Remove the 'instant ADD' status of a clustered index when the table becomes empty, or the very first instant ADD COLUMN operation is rolled back. dict_table_t: Add the accessors is_instant(), is_temporary(), supports_instant(). dict_table_t::instant_add_column(): Adjust metadata for instant ADD COLUMN. dict_table_t::rollback_instant(): Adjust metadata on the rollback of instant ADD COLUMN. prepare_inplace_alter_table_dict(): First create the ctx->new_table, and only then decide if the table really needs to be rebuilt. We must split the creation of table or index metadata from the creation of the dictionary table records and the creation of the data. In this way, we can transform a table-rebuilding operation into an instant ADD COLUMN operation. Dictionary objects will only be added to cache when table rebuilding or index creation is needed. The ctx->instant_table will never be added to cache. dict_table_t::add_to_cache(): Modified and renamed from dict_table_add_to_cache(). Do not modify the table metadata. Let the callers invoke dict_table_add_system_columns() and if needed, set can_be_evicted. dict_create_sys_tables_tuple(), dict_create_table_step(): Omit the system columns (which will now exist in the dict_table_t object already at this point). dict_create_table_step(): Expect the callers to invoke dict_table_add_system_columns(). pars_create_table(): Before creating the table creation execution graph, invoke dict_table_add_system_columns(). row_create_table_for_mysql(): Expect all callers to invoke dict_table_add_system_columns(). create_index_dict(): Replaces row_merge_create_index_graph(). innodb_update_n_cols(): Renamed from innobase_update_n_virtual(). Call my_error() if an error occurs. btr_cur_instant_init(), btr_cur_instant_init_low(), btr_cur_instant_root_init(): Load additional metadata from the clustered index and set dict_index_t::n_core_null_bytes. This is invoked when table metadata is first loaded into the data dictionary. dict_boot(): Initialize n_core_null_bytes for the four hard-coded dictionary tables. dict_create_index_step(): Initialize n_core_null_bytes. This is executed as part of CREATE TABLE. dict_index_build_internal_clust(): Initialize n_core_null_bytes to NO_CORE_NULL_BYTES if table->supports_instant(). row_create_index_for_mysql(): Initialize n_core_null_bytes for CREATE TEMPORARY TABLE. commit_cache_norebuild(): Call the code to rename or enlarge columns in the cache only if instant ADD COLUMN is not being used. (Instant ADD COLUMN would copy all column metadata from instant_table to old_table, including the names and lengths.) PAGE_INSTANT: A new 13-bit field for storing dict_index_t::n_core_fields. This is repurposing the 16-bit field PAGE_DIRECTION, of which only the least significant 3 bits were used. The original byte containing PAGE_DIRECTION will be accessible via the new constant PAGE_DIRECTION_B. page_get_instant(), page_set_instant(): Accessors for the PAGE_INSTANT. page_ptr_get_direction(), page_get_direction(), page_ptr_set_direction(): Accessors for PAGE_DIRECTION. page_direction_reset(): Reset PAGE_DIRECTION, PAGE_N_DIRECTION. page_direction_increment(): Increment PAGE_N_DIRECTION and set PAGE_DIRECTION. rec_get_offsets(): Use the 'leaf' parameter for non-debug purposes, and assume that heap_no is always set. Initialize all dict_index_t::n_fields for ROW_FORMAT=REDUNDANT records, even if the record contains fewer fields. rec_offs_make_valid(): Add the parameter 'leaf'. rec_copy_prefix_to_dtuple(): Assert that the tuple is only built on the core fields. Instant ADD COLUMN only applies to the clustered index, and we should never build a search key that has more than the PRIMARY KEY and possibly DB_TRX_ID,DB_ROLL_PTR. All these columns are always present. dict_index_build_data_tuple(): Remove assertions that would be duplicated in rec_copy_prefix_to_dtuple(). rec_init_offsets(): Support ROW_FORMAT=REDUNDANT records whose number of fields is between n_core_fields and n_fields. cmp_rec_rec_with_match(): Implement the comparison between two MIN_REC_FLAG records. trx_t::in_rollback: Make the field available in non-debug builds. trx_start_for_ddl_low(): Remove dangerous error-tolerance. A dictionary transaction must be flagged as such before it has generated any undo log records. This is because trx_undo_assign_undo() will mark the transaction as a dictionary transaction in the undo log header right before the very first undo log record is being written. btr_index_rec_validate(): Account for instant ADD COLUMN row_undo_ins_remove_clust_rec(): On the rollback of an insert into SYS_COLUMNS, revert instant ADD COLUMN in the cache by removing the last column from the table and the clustered index. row_search_on_row_ref(), row_undo_mod_parse_undo_rec(), row_undo_mod(), trx_undo_update_rec_get_update(): Handle the 'default row' as a special case. dtuple_t::trim(index): Omit a redundant suffix of an index tuple right before insert or update. After instant ADD COLUMN, if the last fields of a clustered index tuple match the 'default row', there is no need to store them. While trimming the entry, we must hold a page latch, so that the table cannot be emptied and the 'default row' be deleted. btr_cur_optimistic_update(), btr_cur_pessimistic_update(), row_upd_clust_rec_by_insert(), row_ins_clust_index_entry_low(): Invoke dtuple_t::trim() if needed. row_ins_clust_index_entry(): Restore dtuple_t::n_fields after calling row_ins_clust_index_entry_low(). rec_get_converted_size(), rec_get_converted_size_comp(): Allow the number of fields to be between n_core_fields and n_fields. Do not support infimum,supremum. They are never supposed to be stored in dtuple_t, because page creation nowadays uses a lower-level method for initializing them. rec_convert_dtuple_to_rec_comp(): Assign the status bits based on the number of fields. btr_cur_trim(): In an update, trim the index entry as needed. For the 'default row', handle rollback specially. For user records, omit fields that match the 'default row'. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): Skip locking and adaptive hash index for the 'default row'. row_log_table_apply_convert_mrec(): Replace 'default row' values if needed. In the temporary file that is applied by row_log_table_apply(), we must identify whether the records contain the extra header for instantly added columns. For now, we will allocate an additional byte for this for ROW_T_INSERT and ROW_T_UPDATE records when the source table has been subject to instant ADD COLUMN. The ROW_T_DELETE records are fine, as they will be converted and will only contain 'core' columns (PRIMARY KEY and some system columns) that are converted from dtuple_t. rec_get_converted_size_temp(), rec_init_offsets_temp(), rec_convert_dtuple_to_temp(): Add the parameter 'status'. REC_INFO_DEFAULT_ROW = REC_INFO_MIN_REC_FLAG | REC_STATUS_COLUMNS_ADDED: An info_bits constant for distinguishing the 'default row' record. rec_comp_status_t: An enum of the status bit values. rec_leaf_format: An enum that replaces the bool parameter of rec_init_offsets_comp_ordinary().
2017-10-06 07:00:05 +03:00
SELECT variable_value-@old_instant instants
FROM information_schema.global_status
WHERE variable_name = 'innodb_instant_alter_column';
MDEV-20590 Introduce a file format constraint to ALTER TABLE If a table is altered using the MDEV-11369/MDEV-15562/MDEV-13134 ALGORITHM=INSTANT, it can force the table to use a non-canonical format: * A hidden metadata record at the start of the clustered index is used to store each column's DEFAULT value. This makes it possible to add new columns that have default values without rebuilding the table. * Starting with MDEV-15562 in MariaDB Server 10.4, a BLOB in the hidden metadata record is used to store column mappings. This makes it possible to drop or reorder columns without rebuilding the table. This also makes it possible to add columns to any position or drop columns from any position in the table without rebuilding the table. If a column is dropped without rebuilding the table, old records will contain garbage in that column's former position, and new records will be written with NULL values, empty strings, or dummy values. This is generally not a problem. However, there may be cases where users may want to avoid putting a table into this format. For example, users may want to ensure that future UPDATE operations after an ADD COLUMN will be performed in-place, to reduce write amplification. (Instantly added columns are essentially always variable-length.) Users might also want to avoid bugs similar to MDEV-19916, or they may want to be able to export tables to older versions of the server. We will introduce the option innodb_instant_alter_column_allowed, with the following values: * never (0): Do not allow instant add/drop/reorder, to maintain format compatibility with MariaDB 10.x and MySQL 5.x. If the table (or partition) is not in the canonical format, then any ALTER TABLE (even one that does not involve instant column operations) will force a table rebuild. * add_last (1, default in 10.3): Store a hidden metadata record that allows columns to be appended to the table instantly (MDEV-11369). In 10.4 or later, if the table (or partition) is not in this format, then any ALTER TABLE (even one that does not involve column changes) will force a table rebuild. Starting with 10.4: * add_drop_reorder (2, default): Like 'add_last', but allow the metadata record to store a column map, to support instant add/drop/reorder of columns (MDEV-15562).
2020-03-30 12:31:54 +03:00
SET GLOBAL innodb_instant_alter_column_allowed = @saved_allowance;
--echo #
--echo # MDEV-18266: Changing an index comment unnecessarily rebuilds index
--echo #
CREATE TABLE t1(a INT, b INT) ENGINE=INNODB;
CREATE INDEX i1 ON t1(a) COMMENT 'comment1';
ALTER TABLE t1 DROP INDEX i1, ADD INDEX i1(a) COMMENT 'comment2', ALGORITHM=INSTANT;
SHOW CREATE TABLE t1;
DROP TABLE t1;
--echo #
--echo # MDEV-25057 Assertion `n_fields < dtuple_get_n_fields(entry)'
--echo # failed in dtuple_convert_big_rec
--echo #
CREATE TABLE t1 (pk INT PRIMARY KEY AUTO_INCREMENT,
a CHAR(255) NOT NULL,
b CHAR(255) NOT NULL, c INT) ENGINE=InnoDB CHARSET utf32;
ALTER TABLE t1 DROP c;
INSERT INTO t1(a, b) SELECT '', '' FROM seq_1_to_16;
SELECT COUNT(*) FROM t1;
# Cleanup
DROP TABLE t1;
--echo #
--echo # MDEV-25630 Rollback of instant operation adds wrong
--echo # column to secondary index
--echo #
CREATE TABLE t1 (f1 INT, f2 INT, f3 INT, f4 INT,
PRIMARY KEY(f1, f4),
KEY(f2))ENGINE=InnoDB;
CREATE TABLE t2 (f1 INT, f2 INT, PRIMARY KEY(f1),
FOREIGN KEY fk (f2) REFERENCES t2(f1)
)ENGINE=InnoDB;
ALTER TABLE t1 ADD f5 INT;
SET FOREIGN_KEY_CHECKS=0;
--error ER_FK_FAIL_ADD_SYSTEM
ALTER TABLE t1 DROP COLUMN f3, ADD FOREIGN KEY fk (f1)
REFERENCES x(x);
ALTER TABLE t1 DROP COLUMN f5;
SHOW CREATE TABLE t1;
DROP TABLE t1, t2;
--echo #
--echo # MDEV-28822 Table from older version requires table rebuild when adding column to table with multi-column index
--echo #
CREATE TABLE mdev28822_100427_innodb (
id int not null primary key,
msg varchar(10),
index(id, msg)
) ENGINE=InnoDB ROW_FORMAT=DYNAMIC;
FLUSH TABLES;
remove_file $datadir/test/mdev28822_100427_innodb.frm;
copy_file std_data/mysql_upgrade/mdev28822_100427_innodb.frm $datadir/test/mdev28822_100427_innodb.frm;
ALTER TABLE mdev28822_100427_innodb ADD i1 INTEGER, ALGORITHM=INSTANT;
DROP TABLE mdev28822_100427_innodb;
SET GLOBAL innodb_stats_persistent = @save_stats_persistent;