REPLACE INTO statements would now use my_charset_utf8mb4_bin conversion
Also, the sql_script file structure would now look like
SET NAMES utf8mb4;
SET var1=value1;
.
.
CREATE DATABASE 'name' if NOT..;
USE DATABASE 'name';
CREATE TABLE ...;
.
REPLACE INTO ..;
.
.
set @opt_context='...';
.
.
Additionally, made few changes to the documentation comments
This task loads the stats of the tables that are used in a query,
from the trace into the optimizer. This feature is controlled
by optimizer_replay_context, and points to an user defined variable name,
that has the context information.
The stats such as num_of_records present in the table, indexes if present,
their names, along with the average number of records_per_key
with in each index, cost of reading an index are loaded from the trace.
Additionally, stats from range analysis i.e. ranges, and the
corresponding number of records, along with their costs are also
loaded from the trace.
The trace context which is in JSON format is firstly set into the
user defined session variable, and this variable name is set to
optimizer_replay_context system variable.
Later, when a user issues a query, the contents of the json context is
parsed and an in memory representation is built using the class
Optimizer_context_replay. This class is then used by the optimizer
to update and save original values of the tables, indexes, and range stats
in the methods "set_statistics_for_table()" of sql_statistics.cc, and
"check_quick_select()" of opt_range.cc.
After the query gets finished, the statistics that were updated
in the optimizer are restored back to the saved original values.
The entry point for parsing the json structure is in
"mysql_execute_command()" of sql_parse.cc, and similarly exit point
i.e. to restore the saved stats of the optimizer is at the end
of the same method.
Two new warning/error messages are introduced:
ER_JSON_OPTIMIZER_REPLAY_CONTEXT_PARSE_FAILED, and
ER_JSON_OPTIMIZER_REPLAY_CONTEXT_MATCH_FAILED
Introduce CAN_BE_NULL annotation into Table_check_intact checks.
By default columns are considered NOT NULL, nullable
columns must be explicitly marked with CAN_BE_NULL.
All TABLE_FIELD_TYPE arrays are fixed as above.
Assisted-By: Claude:claude-4.6-sonnet
The NULL-aware index statistics fix is now controlled by the
FIX_INDEX_STATS_FOR_ALL_NULLS flag and disabled by default
for preserving execution plan stability in stable versions.
To enable:
SET @@new_mode = 'FIX_INDEX_STATS_FOR_ALL_NULLS';
Or via command line:
--new-mode=FIX_INDEX_STATS_FOR_ALL_NULLS
Or in configuration file:
[mysqld]
new_mode=FIX_INDEX_STATS_FOR_ALL_NULLS
`all_nulls_key_parts` bitmap is now calculated at set_statistics_for_table()
(Preparation for the main patch)
set_statistics_for_table() incorrectly treated indexes with all NULL
values the same as indexes with no statistics, because avg_frequency
is 0 in both cases. This caused the optimizer to ignore valid EITS
data and fall back to engine statistics.
Additionally, KEY::actual_rec_per_key() would fall back to engine
statistics even when EITS was available, and used incorrect pointer
comparison (rec_per_key == 0 instead of nullptr).
Fix by adding Index_statistics::stats_were_read flag to track per-index
whether statistics were actually read from persistent tables, and
restructuring actual_rec_per_key() to prioritize EITS when available.
- Removed duplicate words, like "the the" and "to to"
- Removed duplicate lines (one double sort line found in mysql.cc)
- Fixed some typos found while searching for duplicate words.
Command used to find duplicate words:
egrep -rI "\s([a-zA-Z]+)\s+\1\s" | grep -v param
Thanks to Artjoms Rimdjonoks for the command and pointing out the
spelling errors.
rename_table_in_stat_tables(): Allocate TABLE_LIST[STATISTICS_TABLES]
from the heap instead of the stack, to pass -Wframe-larger-than=16384
in an optimized CMAKE_BUILD_TYPE=RelWithDebInfo build.
page_is_corrupted(): Do not allocate the buffers from stack,
but from the heap, in xb_fil_cur_open().
row_quiesce_write_cfg(): Issue one type of message when we
fail to create the .cfg file.
update_statistics_for_table(), read_statistics_for_table(),
delete_statistics_for_table(), rename_table_in_stat_tables():
Use a common stack buffer for Index_stat, Column_stat, Table_stat.
ha_connect::FileExists(): Invoke push_warning_printf() so that
we can avoid allocating a buffer for snprintf().
translog_init_with_table(): Do not duplicate TRANSLOG_PAGE_SIZE_BUFF.
Let us also globally enable the GCC 4.4 and clang 3.0 option
-Wframe-larger-than=16384 to reduce the possibility of introducing
such stack overflow in the future. For RocksDB and Mroonga we relax
these limits.
Reviewed by: Vladislav Lesin
* Let GCC `-Wformat` check formats sent to these `my_vsnprintf_ex` users
* Migrate them from the old extension specifiers
to the new `-Wformat`-compatible suffixes
Partial commit of the greater MDEV-34348 scope.
MDEV-34348: MariaDB is violating clang-16 -Wcast-function-type-strict
The functions queue_compare, qsort2_cmp, and qsort_cmp2
all had similar interfaces, and were used interchangable
and unsafely cast to one another.
This patch consolidates the functions all into the
qsort_cmp2 interface.
Reviewed By:
============
Marko Mäkelä <marko.makela@mariadb.com>
create templates
thd->alloc<X>(n) to use instead of (X*)thd->alloc(sizeof(X)*n)
and the same for thd->calloc(). By the default the type is char,
so old usage of thd->alloc(size) works too.
the information about index algorithm was stored in two
places inconsistently split between both.
BTREE index could have key->algorithm == HA_KEY_ALG_BTREE, if the user
explicitly specified USING BTREE or HA_KEY_ALG_UNDEF, if not.
RTREE index had key->algorithm == HA_KEY_ALG_RTREE
and always had key->flags & HA_SPATIAL
FULLTEXT index had key->algorithm == HA_KEY_ALG_FULLTEXT
and always had key->flags & HA_FULLTEXT
HASH index had key->algorithm == HA_KEY_ALG_HASH or HA_KEY_ALG_UNDEF
long unique index always had key->algorithm == HA_KEY_ALG_LONG_HASH
In this commit:
All indexes except BTREE and HASH always have key->algorithm
set, HA_SPATIAL and HA_FULLTEXT flags are not used anymore (except
for storage to keep frms backward compatible).
As a side effect ALTER TABLE now detects FULLTEXT index renames correctly
Two new variables added:
- max_tmp_space_usage : Limits the the temporary space allowance per user
- max_total_tmp_space_usage: Limits the temporary space allowance for
all users.
New status variables: tmp_space_used & max_tmp_space_used
New field in information_schema.process_list: TMP_SPACE_USED
The temporary space is counted for:
- All SQL level temporary files. This includes files for filesort,
transaction temporary space, analyze, binlog_stmt_cache etc.
It does not include engine internal temporary files used for repair,
alter table, index pre sorting etc.
- All internal on disk temporary tables created as part of resolving a
SELECT, multi-source update etc.
Special cases:
- When doing a commit, the last flush of the binlog_stmt_cache
will not cause an error even if the temporary space limit is exceeded.
This is to avoid giving errors on commit. This means that a user
can temporary go over the limit with up to binlog_stmt_cache_size.
Noteworthy issue:
- One has to be careful when using small values for max_tmp_space_limit
together with binary logging and with non transactional tables.
If a the binary log entry for the query is bigger than
binlog_stmt_cache_size and one hits the limit of max_tmp_space_limit
when flushing the entry to disk, the query will abort and the
binary log will not contain the last changes to the table.
This will also stop the slave!
This is also true for all Aria tables as Aria cannot do rollback
(except in case of crashes)!
One way to avoid it is to use @@binlog_format=statement for
queries that updates a lot of rows.
Implementation:
- All writes to temporary files or internal temporary tables, that
increases the file size, are routed through temp_file_size_cb_func()
which updates and checks the temp space usage.
- Most of the temporary file monitoring is done inside IO_CACHE.
Temporary file monitoring is done inside the Aria engine.
- MY_TRACK and MY_TRACK_WITH_LIMIT are new flags for ini_io_cache().
MY_TRACK means that we track the file usage. TRACK_WITH_LIMIT means
that we track the file usage and we give an error if the limit is
breached. This is used to not give an error on commit when
binlog_stmp_cache is flushed.
- global_tmp_space_used contains the total tmp space used so far.
This is needed quickly check against max_total_tmp_space_usage.
- Temporary space errors are using EE_LOCAL_TMP_SPACE_FULL and
handler errors are using HA_ERR_LOCAL_TMP_SPACE_FULL.
This is needed until we move general errors to it's own error space
so that they cannot conflict with system error numbers.
- Return value of my_chsize() and mysql_file_chsize() has changed
so that -1 is returned in the case my_chsize() could not decrease
the file size (very unlikely and will not happen on modern systems).
All calls to _chsize() are updated to check for > 0 as the error
condition.
- At the destruction of THD we check that THD::tmp_file_space == 0
- At server end we check that global_tmp_space_used == 0
- As a precaution against errors in the tmp_space_used code, one can set
max_tmp_space_usage and max_total_tmp_space_usage to 0 to disable
the tmp space quota errors.
- truncate_io_cache() function added.
- Aria tables using static or dynamic row length are registered in 8K
increments to avoid some calls to update_tmp_file_size().
Other things:
- Ensure that all handler errors are registered. Before, some engine
errors could be printed as "Unknown error".
- Fixed bug in filesort() that causes a assert if there was an error
when writing to the temporay file.
- Fixed that compute_window_func() now takes into account write errors.
- In case of parallel replication, rpl_group_info::cleanup_context()
could call trans_rollback() with thd->error set, which would cause
an assert. Fixed by resetting the error before calling trans_rollback().
- Fixed bug in subselect3.inc which caused following test to use
heap tables with low value for max_heap_table_size
- Fixed bug in sql_expression_cache where it did not overflow
heap table to Aria table.
- Added Max_tmp_disk_space_used to slow query log.
- Fixed some bugs in log_slow_innodb.test
