mariadb/storage/innobase/include/row0merge.h
Marko Mäkelä f8240a2723 MDEV-26294 Duplicate entries in unique index not detected when changing collation
Problem:
=======
ALTER TABLE in InnoDB fails to detect duplicate entries
for the unique index when the character set or collation of
an indexed column is changed in such a way that the character
encoding is compatible with the old table definition.
In this case, any secondary indexes on the changed columns
would be rebuilt (DROP INDEX, ADD INDEX).

Solution:
========
During ALTER TABLE, InnoDB keeps track of columns whose collation
changed, and will fill in the correct metadata when sorting the
index records, or applying changes from concurrent DML.
This metadata will be allocated in the dict_index_t::heap of
the being-created secondary indexes.

The fix was developed by Thirunarayanan Balathandayuthapani
and simplified by me.
2022-07-04 16:13:04 +03:00

419 lines
15 KiB
C++

/*****************************************************************************
Copyright (c) 2005, 2016, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2015, 2022, MariaDB Corporation.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
*****************************************************************************/
/**************************************************//**
@file include/row0merge.h
Index build routines using a merge sort
Created 13/06/2005 Jan Lindstrom
*******************************************************/
#ifndef row0merge_h
#define row0merge_h
#include "que0types.h"
#include "trx0types.h"
#include "mtr0mtr.h"
#include "rem0types.h"
#include "rem0rec.h"
#include "btr0types.h"
#include "row0mysql.h"
#include "lock0types.h"
#include "srv0srv.h"
#include "ut0stage.h"
/* Reserve free space from every block for key_version */
#define ROW_MERGE_RESERVE_SIZE 4
/* Cluster index read task is mandatory */
#define COST_READ_CLUSTERED_INDEX 1.0
/* Basic fixed cost to build all type of index */
#define COST_BUILD_INDEX_STATIC 0.5
/* Dynamic cost to build all type of index, dynamic cost will be re-distributed based on page count ratio of each index */
#define COST_BUILD_INDEX_DYNAMIC 0.5
/* Sum of below two must be 1.0 */
#define PCT_COST_MERGESORT_INDEX 0.4
#define PCT_COST_INSERT_INDEX 0.6
// Forward declaration
struct ib_sequence_t;
/** @brief Block size for I/O operations in merge sort.
The minimum is srv_page_size, or page_get_free_space_of_empty()
rounded to a power of 2.
When not creating a PRIMARY KEY that contains column prefixes, this
can be set as small as srv_page_size / 2. */
typedef byte row_merge_block_t;
/** @brief Secondary buffer for I/O operations of merge records.
This buffer is used for writing or reading a record that spans two
row_merge_block_t. Thus, it must be able to hold one merge record,
whose maximum size is the same as the minimum size of
row_merge_block_t. */
typedef byte mrec_buf_t[UNIV_PAGE_SIZE_MAX];
/** @brief Merge record in row_merge_block_t.
The format is the same as a record in ROW_FORMAT=COMPACT with the
exception that the REC_N_NEW_EXTRA_BYTES are omitted. */
typedef byte mrec_t;
/** Merge record in row_merge_buf_t */
struct mtuple_t {
dfield_t* fields; /*!< data fields */
};
/** Buffer for sorting in main memory. */
struct row_merge_buf_t {
mem_heap_t* heap; /*!< memory heap where allocated */
dict_index_t* index; /*!< the index the tuples belong to */
ulint total_size; /*!< total amount of data bytes */
ulint n_tuples; /*!< number of data tuples */
ulint max_tuples; /*!< maximum number of data tuples */
mtuple_t* tuples; /*!< array of data tuples */
mtuple_t* tmp_tuples; /*!< temporary copy of tuples,
for sorting */
};
/** Information about temporary files used in merge sort */
struct merge_file_t {
pfs_os_file_t fd; /*!< file descriptor */
ulint offset; /*!< file offset (end of file) */
ib_uint64_t n_rec; /*!< number of records in the file */
};
/** Index field definition */
struct index_field_t {
ulint col_no; /*!< column offset */
ulint prefix_len; /*!< column prefix length, or 0
if indexing the whole column */
bool is_v_col; /*!< whether this is a virtual column */
};
/** Definition of an index being created */
struct index_def_t {
const char* name; /*!< index name */
bool rebuild; /*!< whether the table is rebuilt */
ulint ind_type; /*!< 0, DICT_UNIQUE,
or DICT_CLUSTERED */
ulint key_number; /*!< MySQL key number,
or ULINT_UNDEFINED if none */
ulint n_fields; /*!< number of fields in index */
index_field_t* fields; /*!< field definitions */
st_mysql_ftparser*
parser; /*!< fulltext parser plugin */
};
/** Structure for reporting duplicate records. */
struct row_merge_dup_t {
dict_index_t* index; /*!< index being sorted */
struct TABLE* table; /*!< MySQL table object */
const ulint* col_map;/*!< mapping of column numbers
in table to the rebuilt table
(index->table), or NULL if not
rebuilding table */
ulint n_dup; /*!< number of duplicates */
};
/*************************************************************//**
Report a duplicate key. */
void
row_merge_dup_report(
/*=================*/
row_merge_dup_t* dup, /*!< in/out: for reporting duplicates */
const dfield_t* entry) /*!< in: duplicate index entry */
MY_ATTRIBUTE((nonnull));
/** Drop indexes that were created before an error occurred.
The data dictionary must have been locked exclusively by the caller,
because the transaction will not be committed.
@param trx dictionary transaction
@param table table containing the indexes
@param locked True if table is locked,
false - may need to do lazy drop
@param alter_trx Alter table transaction */
void
row_merge_drop_indexes(
trx_t* trx,
dict_table_t* table,
bool locked,
const trx_t* alter_trx=NULL);
/** During recovery, drop recovered index stubs that were created in
prepare_inplace_alter_table_dict(). */
void row_merge_drop_temp_indexes();
/** Create temporary merge files in the given paramater path, and if
UNIV_PFS_IO defined, register the file descriptor with Performance Schema.
@param[in] path location for creating temporary merge files, or NULL
@return File descriptor */
pfs_os_file_t
row_merge_file_create_low(
const char* path)
MY_ATTRIBUTE((warn_unused_result));
/*********************************************************************//**
Destroy a merge file. And de-register the file from Performance Schema
if UNIV_PFS_IO is defined. */
void
row_merge_file_destroy_low(
/*=======================*/
const pfs_os_file_t& fd); /*!< in: merge file descriptor */
/*********************************************************************//**
Rename an index in the dictionary that was created. The data
dictionary must have been locked exclusively by the caller, because
the transaction will not be committed.
@return DB_SUCCESS if all OK */
dberr_t
row_merge_rename_index_to_add(
/*==========================*/
trx_t* trx, /*!< in/out: transaction */
table_id_t table_id, /*!< in: table identifier */
index_id_t index_id) /*!< in: index identifier */
MY_ATTRIBUTE((nonnull(1), warn_unused_result));
/** Create the index and load in to the dictionary.
@param[in,out] table the index is on this table
@param[in] index_def the index definition
@param[in] add_v new virtual columns added along with add
index call
@return index, or NULL on error */
dict_index_t*
row_merge_create_index(
dict_table_t* table,
const index_def_t* index_def,
const dict_add_v_col_t* add_v)
MY_ATTRIBUTE((warn_unused_result));
/*********************************************************************//**
Check if a transaction can use an index.
@return whether the index can be used by the transaction */
bool
row_merge_is_index_usable(
/*======================*/
const trx_t* trx, /*!< in: transaction */
const dict_index_t* index) /*!< in: index to check */
MY_ATTRIBUTE((nonnull, warn_unused_result));
/** Map from column numbers to column definitions that include
changes to the collation, when the encoding is compatible with
the original column and no table rebuild is needed */
typedef std::map<unsigned, dict_col_t*> col_collations;
/** Build indexes on a table by reading a clustered index, creating a temporary
file containing index entries, merge sorting these index entries and inserting
sorted index entries to indexes.
@param[in] trx transaction
@param[in] old_table table where rows are read from
@param[in] new_table table where indexes are created; identical to
old_table unless creating a PRIMARY KEY
@param[in] online true if creating indexes online
@param[in] indexes indexes to be created
@param[in] key_numbers MySQL key numbers
@param[in] n_indexes size of indexes[]
@param[in,out] table MySQL table, for reporting erroneous key value
if applicable
@param[in] defaults default values of added, changed columns, or NULL
@param[in] col_map mapping of old column numbers to new ones, or
NULL if old_table == new_table
@param[in] add_autoinc number of added AUTO_INCREMENT columns, or
ULINT_UNDEFINED if none is added
@param[in,out] sequence autoinc sequence
@param[in] skip_pk_sort whether the new PRIMARY KEY will follow
existing order
@param[in,out] stage performance schema accounting object, used by
ALTER TABLE. stage->begin_phase_read_pk() will be called at the beginning of
this function and it will be passed to other functions for further accounting.
@param[in] add_v new virtual columns added along with indexes
@param[in] eval_table mysql table used to evaluate virtual column
value, see innobase_get_computed_value().
@param[in] allow_non_null allow the conversion from null to not-null
@param[in] col_collate columns whose collations changed, or nullptr
@return DB_SUCCESS or error code */
dberr_t
row_merge_build_indexes(
trx_t* trx,
dict_table_t* old_table,
dict_table_t* new_table,
bool online,
dict_index_t** indexes,
const ulint* key_numbers,
ulint n_indexes,
struct TABLE* table,
const dtuple_t* defaults,
const ulint* col_map,
ulint add_autoinc,
ib_sequence_t& sequence,
bool skip_pk_sort,
ut_stage_alter_t* stage,
const dict_add_v_col_t* add_v,
struct TABLE* eval_table,
bool allow_non_null,
const col_collations* col_collate)
MY_ATTRIBUTE((warn_unused_result));
/********************************************************************//**
Write a buffer to a block. */
void
row_merge_buf_write(
/*================*/
const row_merge_buf_t* buf, /*!< in: sorted buffer */
const merge_file_t* of, /*!< in: output file */
row_merge_block_t* block) /*!< out: buffer for writing to file */
MY_ATTRIBUTE((nonnull));
/********************************************************************//**
Sort a buffer. */
void
row_merge_buf_sort(
/*===============*/
row_merge_buf_t* buf, /*!< in/out: sort buffer */
row_merge_dup_t* dup) /*!< in/out: reporter of duplicates
(NULL if non-unique index) */
MY_ATTRIBUTE((nonnull(1)));
/********************************************************************//**
Write a merge block to the file system.
@return whether the request was completed successfully
@retval false on error
@retval true on success */
bool
row_merge_write(
const pfs_os_file_t& fd, /*!< in: file descriptor */
ulint offset, /*!< in: offset where to write,
in number of row_merge_block_t elements */
const void* buf, /*!< in: data */
void* crypt_buf, /*!< in: crypt buf or NULL */
ulint space) /*!< in: space id */
MY_ATTRIBUTE((warn_unused_result));
/********************************************************************//**
Empty a sort buffer.
@return sort buffer */
row_merge_buf_t*
row_merge_buf_empty(
/*================*/
row_merge_buf_t* buf) /*!< in,own: sort buffer */
MY_ATTRIBUTE((warn_unused_result, nonnull));
/** Create a merge file in the given location.
@param[out] merge_file merge file structure
@param[in] path location for creating temporary file, or NULL
@return file descriptor, or -1 on failure */
pfs_os_file_t
row_merge_file_create(
merge_file_t* merge_file,
const char* path)
MY_ATTRIBUTE((warn_unused_result, nonnull(1)));
/** Merge disk files.
@param[in] trx transaction
@param[in] dup descriptor of index being created
@param[in,out] file file containing index entries
@param[in,out] block 3 buffers
@param[in,out] tmpfd temporary file handle
@param[in] update_progress true, if we should update progress status
@param[in] pct_progress total progress percent until now
@param[in] pct_ocst current progress percent
@param[in] crypt_block crypt buf or NULL
@param[in] space space_id
@param[in,out] stage performance schema accounting object, used by
ALTER TABLE. If not NULL, stage->begin_phase_sort() will be called initially
and then stage->inc() will be called for each record processed.
@return DB_SUCCESS or error code */
dberr_t
row_merge_sort(
/*===========*/
trx_t* trx,
const row_merge_dup_t* dup,
merge_file_t* file,
row_merge_block_t* block,
pfs_os_file_t* tmpfd,
const bool update_progress,
const double pct_progress,
const double pct_cost,
row_merge_block_t* crypt_block,
ulint space,
ut_stage_alter_t* stage = NULL)
MY_ATTRIBUTE((warn_unused_result));
/*********************************************************************//**
Allocate a sort buffer.
@return own: sort buffer */
row_merge_buf_t*
row_merge_buf_create(
/*=================*/
dict_index_t* index) /*!< in: secondary index */
MY_ATTRIBUTE((warn_unused_result, nonnull, malloc));
/*********************************************************************//**
Deallocate a sort buffer. */
void
row_merge_buf_free(
/*===============*/
row_merge_buf_t* buf) /*!< in,own: sort buffer to be freed */
MY_ATTRIBUTE((nonnull));
/*********************************************************************//**
Destroy a merge file. */
void
row_merge_file_destroy(
/*===================*/
merge_file_t* merge_file) /*!< in/out: merge file structure */
MY_ATTRIBUTE((nonnull));
/** Read a merge block from the file system.
@return whether the request was completed successfully */
bool
row_merge_read(
/*===========*/
const pfs_os_file_t& fd, /*!< in: file descriptor */
ulint offset, /*!< in: offset where to read
in number of row_merge_block_t
elements */
row_merge_block_t* buf, /*!< out: data */
row_merge_block_t* crypt_buf, /*!< in: crypt buf or NULL */
ulint space) /*!< in: space id */
MY_ATTRIBUTE((warn_unused_result));
/********************************************************************//**
Read a merge record.
@return pointer to next record, or NULL on I/O error or end of list */
const byte*
row_merge_read_rec(
/*===============*/
row_merge_block_t* block, /*!< in/out: file buffer */
mrec_buf_t* buf, /*!< in/out: secondary buffer */
const byte* b, /*!< in: pointer to record */
const dict_index_t* index, /*!< in: index of the record */
const pfs_os_file_t& fd, /*!< in: file descriptor */
ulint* foffs, /*!< in/out: file offset */
const mrec_t** mrec, /*!< out: pointer to merge record,
or NULL on end of list
(non-NULL on I/O error) */
rec_offs* offsets,/*!< out: offsets of mrec */
row_merge_block_t* crypt_block, /*!< in: crypt buf or NULL */
ulint space) /*!< in: space id */
MY_ATTRIBUTE((warn_unused_result));
#endif /* row0merge.h */