The assertion failed in handler::ha_reset upon SELECT under
READ UNCOMMITTED from table with index on virtual column.
This was the debug-only failure, though the problem is mush wider:
* MY_BITMAP is a structure containing my_bitmap_map, the latter is a raw
bitmap.
* read_set, write_set and vcol_set of TABLE are the pointers to MY_BITMAP
* The rest of MY_BITMAPs are stored in TABLE and TABLE_SHARE
* The pointers to the stored MY_BITMAPs, like orig_read_set etc, and
sometimes all_set and tmp_set, are assigned to the pointers.
* Sometimes tmp_use_all_columns is used to substitute the raw bitmap
directly with all_set.bitmap
* Sometimes even bitmaps are directly modified, like in
TABLE::update_virtual_field(): bitmap_clear_all(&tmp_set) is called.
The last three bullets in the list, when used together (which is mostly
always) make the program flow cumbersome and impossible to follow,
notwithstanding the errors they cause, like this MDEV-17556, where tmp_set
pointer was assigned to read_set, write_set and vcol_set, then its bitmap
was substituted with all_set.bitmap by dbug_tmp_use_all_columns() call,
and then bitmap_clear_all(&tmp_set) was applied to all this.
To untangle this knot, the rule should be applied:
* Never substitute bitmaps! This patch is about this.
orig_*, all_set bitmaps are never substituted already.
This patch changes the following function prototypes:
* tmp_use_all_columns, dbug_tmp_use_all_columns
to accept MY_BITMAP** and to return MY_BITMAP * instead of my_bitmap_map*
* tmp_restore_column_map, dbug_tmp_restore_column_maps to accept
MY_BITMAP* instead of my_bitmap_map*
These functions now will substitute read_set/write_set/vcol_set directly,
and won't touch underlying bitmaps.
There were two newly enabled warnings:
1. cast for a function pointers. Affected sql_analyse.h, mi_write.c
and ma_write.cc, mf_iocache-t.cc, mysqlbinlog.cc, encryption.cc, etc
2. memcpy/memset of nontrivial structures. Fixed as:
* the warning disabled for InnoDB
* TABLE, TABLE_SHARE, and TABLE_LIST got a new method reset() which
does the bzero(), which is safe for these classes, but any other
bzero() will still cause a warning
* Table_scope_and_contents_source_st uses `TABLE_LIST *` (trivial)
instead of `SQL_I_List<TABLE_LIST>` (not trivial) so it's safe to
bzero now.
* added casts in debug_sync.cc and sql_select.cc (for JOIN)
* move assignment method for MDL_request instead of memcpy()
* PARTIAL_INDEX_INTERSECT_INFO::init() instead of bzero()
* remove constructor from READ_RECORD() to make it trivial
* replace some memcpy() with c++ copy assignments
Benefits of this patch:
- Removed a lot of calls to strlen(), especially for field_string
- Strings generated by parser are now const strings, less chance of
accidently changing a string
- Removed a lot of calls with LEX_STRING as parameter (changed to pointer)
- More uniform code
- Item::name_length was not kept up to date. Now fixed
- Several bugs found and fixed (Access to null pointers,
access of freed memory, wrong arguments to printf like functions)
- Removed a lot of casts from (const char*) to (char*)
Changes:
- This caused some ABI changes
- lex_string_set now uses LEX_CSTRING
- Some fucntions are now taking const char* instead of char*
- Create_field::change and after changed to LEX_CSTRING
- handler::connect_string, comment and engine_name() changed to LEX_CSTRING
- Checked printf() related calls to find bugs. Found and fixed several
errors in old code.
- A lot of changes from LEX_STRING to LEX_CSTRING, especially related to
parsing and events.
- Some changes from LEX_STRING and LEX_STRING & to LEX_CSTRING*
- Some changes for char* to const char*
- Added printf argument checking for my_snprintf()
- Introduced null_clex_str, star_clex_string, temp_lex_str to simplify
code
- Added item_empty_name and item_used_name to be able to distingush between
items that was given an empty name and items that was not given a name
This is used in sql_yacc.yy to know when to give an item a name.
- select table_name."*' is not anymore same as table_name.*
- removed not used function Item::rename()
- Added comparision of item->name_length before some calls to
my_strcasecmp() to speed up comparison
- Moved Item_sp_variable::make_field() from item.h to item.cc
- Some minimal code changes to avoid copying to const char *
- Fixed wrong error message in wsrep_mysql_parse()
- Fixed wrong code in find_field_in_natural_join() where real_item() was
set when it shouldn't
- ER_ERROR_ON_RENAME was used with extra arguments.
- Removed some (wrong) ER_OUTOFMEMORY, as alloc_root will already
give the error.
TODO:
- Check possible unsafe casts in plugin/auth_examples/qa_auth_interface.c
- Change code to not modify LEX_CSTRING for database name
(as part of lower_case_table_names)
Working features:
CREATE OR REPLACE [TEMPORARY] SEQUENCE [IF NOT EXISTS] name
[ INCREMENT [ BY | = ] increment ]
[ MINVALUE [=] minvalue | NO MINVALUE ]
[ MAXVALUE [=] maxvalue | NO MAXVALUE ]
[ START [ WITH | = ] start ] [ CACHE [=] cache ] [ [ NO ] CYCLE ]
ENGINE=xxx COMMENT=".."
SELECT NEXT VALUE FOR sequence_name;
SELECT NEXTVAL(sequence_name);
SELECT PREVIOUS VALUE FOR sequence_name;
SELECT LASTVAL(sequence_name);
SHOW CREATE SEQUENCE sequence_name;
SHOW CREATE TABLE sequence_name;
CREATE TABLE sequence-structure ... SEQUENCE=1
ALTER TABLE sequence RENAME TO sequence2;
RENAME TABLE sequence TO sequence2;
DROP [TEMPORARY] SEQUENCE [IF EXISTS] sequence_names
Missing features
- SETVAL(value,sequence_name), to be used with replication.
- Check replication, including checking that sequence tables are marked
not transactional.
- Check that a commit happens for NEXT VALUE that changes table data (may
already work)
- ALTER SEQUENCE. ANSI SQL version of setval.
- Share identical sequence entries to not add things twice to table list.
- testing insert/delete/update/truncate/load data
- Run and fix Alibaba sequence tests (part of mysql-test/suite/sql_sequence)
- Write documentation for NEXT VALUE / PREVIOUS_VALUE
- NEXTVAL in DEFAULT
- Ensure that NEXTVAL in DEFAULT uses database from base table
- Two NEXTVAL for same row should give same answer.
- Oracle syntax sequence_table.nextval, without any FOR or FROM.
- Sequence tables are treated as 'not read constant tables' by SELECT; Would
be better if we would have a separate list for sequence tables so that
select doesn't know about them, except if refereed to with FROM.
Other things done:
- Improved output for safemalloc backtrack
- frm_type_enum changed to Table_type
- Removed lex->is_view and replaced with lex->table_type. This allows
use to more easy check if item is view, sequence or table.
- Added table flag HA_CAN_TABLES_WITHOUT_ROLLBACK, needed for handlers
that want's to support sequences
- Added handler calls:
- engine_name(), to simplify getting engine name for partition and sequences
- update_first_row(), to be able to do efficient sequence implementations.
- Made binlog_log_row() global to be able to call it from ha_sequence.cc
- Added handler variable: row_already_logged, to be able to flag that the
changed row is already logging to replication log.
- Added CF_DB_CHANGE and CF_SCHEMA_CHANGE flags to simplify
deny_updates_if_read_only_option()
- Added sp_add_cfetch() to avoid new conflicts in sql_yacc.yy
- Moved code for add_table_options() out from sql_show.cc::show_create_table()
- Added String::append_longlong() and used it in sql_show.cc to simplify code.
- Added extra option to dd_frm_type() and ha_table_exists to indicate if
the table is a sequence. Needed by DROP SQUENCE to not drop a table.
Don't mark the SEQUENCE engine as XA-capable. The engine never
registers itself for any transaction, so it doesn't matter
whether it is XA-capable or not. The only effect of being
"XA-capable" is breaking the "number of XA-capable engines"
check of TC_LOG_MMAP.
This task is to allow storage engines that can execute GROUP BY or
summary queries efficiently to intercept a full query or sub query from
MariaDB and deliver the result either to the client or to a temporary
table for further processing.
- Added code in sql_select.cc to intercept GROUP BY queries.
Creation of group_by_handler is done after all optimizations to allow
storage engine to benefit of an optimized WHERE clause and suggested
indexes to use.
- Added group by handler to sequence engine and a group_by test suite as
a way to test the new interface.
- Intercept EXPLAIN with a message "Storage engine handles GROUP BY"
libmysqld/CMakeLists.txt:
Added new group_by_handler files
sql/CMakeLists.txt:
Added new group_by_handler files
sql/group_by_handler.cc:
Implementation of group_by_handler functions
sql/group_by_handler.h:
Definition of group_by_handler class
sql/handler.h:
Added handlerton function to create a group_by_handler, if the storage
engine can intercept the query.
sql/item_cmpfunc.cc:
Allow one to evaluate item_equal any time.
sql/sql_select.cc:
Added code to intercept GROUP BY queries
- If all tables are from the same storage engine and the query is
using sum functions, call create_group_by() to check if the storage
engine can intercept the query.
- If yes:
- create a temporary table to hold a GROUP_BY row or result
- In do_select() intercept normal query execution by instead
calling the group_by_handler to get the result
- Intercept EXPLAIN
sql/sql_select.h:
Added handling of group_by_handler
Added caching of the original join tab (needed for cleanup after
group_by handler)
storage/sequence/mysql-test/sequence/group_by.result:
Test group_by_handler interface
storage/sequence/mysql-test/sequence/group_by.test:
Test group_by_handler interface
storage/sequence/sequence.cc:
Added simple group_by_engine for handling COUNT(*) and
SUM(primary_key). This was done as a test of the group_by_handler
interface
support ha_innodb.so as a dynamic plugin.
* remove obsolete *,innodb_plugin.rdiff files
* s/--plugin-load=/--plugin-load-add=/
* MYSQL_PLUGIN_IMPORT glob_hostname[]
* use my_error instead of push_warning_printf(ER_DEFAULT)
* don't use tdc_size and tc_size in a module
update test cases (XtraDB is 5.6.14, InnoDB is 5.6.10)
* copy new tests over
* disable some tests for (old) InnoDB
* delete XtraDB tests that no longer apply
small compatibility changes:
* s/HTON_EXTENDED_KEYS/HTON_SUPPORTS_EXTENDED_KEYS/
* revert unnecessary InnoDB changes to make it a bit closer to the upstream
fix XtraDB to compile on Windows (both as a static and a dynamic plugin)
disable XtraDB on Windows (deadlocks) and where no atomic ops are available (e.g. CentOS 5)
storage/innobase/handler/ha_innodb.cc:
revert few unnecessary changes to make it a bit closer to the original InnoDB
storage/innobase/include/univ.i:
correct the version to match what it was merged from
Fixed sql_discovery.simple failure.
storage/sequence/sequence.cc:
Let sequence share class have unique name to avoid collision with other
classes.
storage/test_sql_discovery/test_sql_discovery.cc:
Let test_sql_discovery share class have unique name to avoid collision with
other classes.
Fixed sequence compilation failure.
storage/sequence/sequence.cc:
Adjusted sequence according to:
WL#4305 - storage-engine private data area per physical table.
Merge of 10.0-mdev26 feature tree into 10.0-base.
Global transaction ID is prepended to each event group in the binlog.
Slave connect can request to start from GTID position instead of specifying
file name/offset of master binlog. This facilitates easy switch to a new
master.
Slave GTID state is stored in a table mysql.rpl_slave_state, which can be
InnoDB to get crash-safe slave state.
GTID includes a replication domain ID, allowing to keep track of distinct
positions for each of multiple masters.
