(With trivial fixes by sergey@mariadb.com)
Added option fix_innodb_cardinality to optimizer_adjust_secondary_key_costs
Using fix_innodb_cardinality disables the 'divide by 2' of rec_per_key_int
in InnoDB that in effect doubles the Cardinality for secondary keys.
This has the biggest effect for indexes where a few rows has the same key
value. Using this may also cause table scans for very small tables (which
in some cases may be better than an index scan).
The user visible effect is that 'SHOW INDEX FROM table_name' will for
InnoDB show the true Cardinality (and not 2x the real value). It will
also allow the optimizer to chose a better index in some cases as the
division by 2 could have a bad effect for tables with 2-5 identical values
per key.
A few notes about using fix_innodb_cardinality:
- It has direct affect for SHOW INDEX FROM table_name. SHOW INDEX
will also update the statistics in table share.
- The effect of fix_innodb_cardinality for query plans or EXPLAIN
is only visible after first open of the table. This is why one must
do a flush tables or use SHOW INDEX for the option to take effect.
- Using fix_innodb_cardinality can thus affect all user in their query
plans if they are using the same tables.
Because of this, it is strongly recommended that one uses
optimizer_adjust_secondary_key_costs=fix_innodb_cardinality mainly
in configuration files to not cause issues for other users.
Trivial batch, using the handler statistics already collected for
the slow query log.
The reason for the changes in test cases was mainly to change to use
select TABLE_SCHEMA ... from information_schema.table_statistics instead
of 'show table_statistics' to avoid future changes to test results
if we add more columns to table_statistics.
Improve performance of queries like
SELECT * FROM t1 WHERE field = NAME_CONST('a', 4);
by, in this example, replacing the WHERE clause with field = 4
in the case of ref access.
The rewrite is done during fix_fields and we disambiguate this
case from other cases of NAME_CONST by inspecting where we are
in parsing. We rely on THD::where to accomplish this. To
improve performance there, we change the type of THD::where to
be an enumeration, so we can avoid string comparisons during
Item_name_const::fix_fields. Consequently, this patch also
changes all usages of THD::where to conform likewise.
Columns added to TABLE_STATISTICS
- ROWS_INSERTED, ROWS_DELETED, ROWS_UPDATED, KEY_READ_HITS and
KEY_READ_MISSES.
Columns added to CLIENT_STATISTICS and USER_STATISTICS:
- KEY_READ_HITS and KEY_READ_MISSES.
User visible changes (except new columns):
- CLIENT_STATISTICS and USER_STATISTICS has columns KEY_READ_HITS and
KEY_READ_MISSES added after column ROWS_UPDATED before SELECT_COMMANDS.
Other changes:
- Do not collect table statistics for system tables like index_stats
table_stats, performance_schema, information_schema etc as the user
has no control of these and the generate noice in the statistics.
- All row variables that are part of user_stats are moved to
'struct rows_stats' to make it easy to clear all of them at once.
- ha_read_key_misses added to STATUS_VAR
Notes:
- userstat.result has a change of numbers of rows for handler_read_key.
This is because use-stat-tables is now disabled for the test.
- Moved writing to binlog_cache from close_thread_tables() to
binlog_commit().
- In select_create() delete cached row events instead of flushing them
to disk. This was done to avoid possible disk write error in this code.
Changes:
- Fixed that MyISAM and Aria parallel repair works with tmp file limit.
This required to add current_thd to all parallel workers and add
protection in my_malloc_size_cb_func() and temp_file_size_cb_func() to
be able to handle shared THD's. I removed the old code in MyISAM to
set current_thd() as only worked when using with virtal indexed
columns and I wanted to keep the Aria and MyISAM code identical.
Other things:
- Improved error messages from Aria parallel repair and
create_internal_tmp_table_from_heap().
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
- FLUSH GLOBAL STATUS now resets most global_status_vars.
At this stage, this is mainly to be used for testing.
- FLUSH SESSION STATUS added as an alias for FLUSH STATUS.
- FLUSH STATUS does not require any privilege (before required RELOAD).
- FLUSH GLOBAL STATUS requires RELOAD privilege.
- All global status reset moved to FLUSH GLOBAL STATUS.
- Replication semisync status variables are now reset by
FLUSH GLOBAL STATUS.
- In test cases, the only changes are:
- Replace FLUSH STATUS with FLUSH GLOBAL STATUS
- Replace FLUSH STATUS with FLUSH STATUS; FLUSH GLOBAL STATUS.
This was only done in a few tests where the test was using SHOW STATUS
for both local and global variables.
- Uptime_since_flush_status is now always provided, independent if
ENABLED_PROFILING is enabled when compiling MariaDB.
- @@global.Uptime_since_flush_status is reset on FLUSH GLOBAL STATUS
and @@session.Uptime_since_flush_status is reset on FLUSH SESSION STATUS.
- When connected, @@session.Uptime_since_flush_status is set to 0.
Remove alter_algorithm but keep the variable as no-op (with a warning).
The reasons for removing alter_algorithm are:
- alter_algorithm was introduced as a replacement for the
old_alter_table that was used to force the usage of the original
alter table algorithm (copy) in the cases where the new alter
algorithm did not work. The new option was added as a way to force
the usage of a specific algorithm when it should instead have made
it possible to disable algorithms that would not work for some
reason.
- alter_algorithm introduced some cases where ALTER TABLE would not
work without specifying the ALGORITHM=XXX option together with
ALTER TABLE.
- Having different values of alter_algorithm on master and slave could
cause slave to stop unexpectedly.
- ALTER TABLE FORCE, as used by mariadb-upgrade, would not always work
if alter_algorithm was set for the server.
- As part of the MDEV-33449 "improving repair of tables" it become
clear that alter- algorithm made it harder to provide a better and
more consistent ALTER TABLE FORCE and REPAIR TABLE and it would be
better to remove it.
MDEV-32188 make TIMESTAMP use whole 32-bit unsigned range
- Changed usage of timeval to my_timeval as the timeval parts on windows
are 32-bit long, which causes some compiler issues on windows.
This is to update the plugin to be compatible with Percona's
query_response_time plugin, with some additions.
Some of the tests are taken from Percona server.
- Added plugins QUERY_RESPONSE_TIME_READ, QUERY_RESPONSE_TIME_WRITE and
QUERY_RESPONSE_TIME_READ_WRITE.
- Added option query_response_time_session_stats, with possible values
GLOBAL, ON or OFF, to the query_response_time plugin.
Notes:
- All modules are dependent on QUERY_RESPONSE_READ_TIME. This must always
be enabled if any of the other modules are used.
This will be auto-enabled in the near future.
- Accounting are done per statement. Stored functions are regarded
as part of the original statement.
- For stored procedures the accounting are done per statement executed
in the stored procedure. CALL will not be accounted because of this.
- FLUSH commands will not be accounted for. This is to ensure that
FLUSH QUERY_RESPONSE_TIME is not part of the statistics.
(This helps when testing with mtr and otherwise).
- FLUSH QUERY_RESPONSE_TIME_READ and FLUSH QUERY_RESPONSE_TIME_READ
only resets the corresponding status.
- FLUSH QUERY_RESPONSE_TIME and FLUSH QUERY_RESPONSE_TIME_READ_WRITE or
changing the value of query_response_time_range_base followed by
any FLUSH of QUERY_RESPOSNSE_TIME resets all status.
The patch for MDEV-31340 fixed the following bugs:
MDEV-33084 LASTVAL(t1) and LASTVAL(T1) do not work well with lower-case-table-names=0
MDEV-33085 Tables T1 and t1 do not work well with ENGINE=CSV and lower-case-table-names=0
MDEV-33086 SHOW OPEN TABLES IN DB1 -- is case insensitive with lower-case-table-names=0
MDEV-33088 Cannot create triggers in the database `MYSQL`
MDEV-33103 LOCK TABLE t1 AS t2 -- alias is not case sensitive with lower-case-table-names=0
MDEV-33108 TABLE_STATISTICS and INDEX_STATISTICS are case insensitive with lower-case-table-names=0
MDEV-33109 DROP DATABASE MYSQL -- does not drop SP with lower-case-table-names=0
MDEV-33110 HANDLER commands are case insensitive with lower-case-table-names=0
MDEV-33119 User is case insensitive in INFORMATION_SCHEMA.VIEWS
MDEV-33120 System log table names are case insensitive with lower-cast-table-names=0
Backporting the fixes from 11.5 to 10.5
When binlog_get_pending_rows_event was refactored, one usage in
binlog_need_stmt_format has not been taken in mind.
As binlog_get_pending_rows_event now requires existing cache_mngr, this check
is now made first.
Fixing the problem that an operation involving a mix of
two or more GEOMETRY operands did not preserve their SRIDs.
Now SRIDs are preserved by hybrid functions, subqueries, TVCs, UNIONs, VIEWs.
Incompatible change:
An attempt to mix two different SRIDs now raises an error.
Details:
- Adding a new class Type_extra_attributes. It's a generic
container which can store very specific data type attributes.
For now it can store one uint32 and one const pointer attribute
(for GEOMETRY's SRID and for ENUM/SET TYPELIB respectively).
In the future it can grow as needed.
Type_extra_attributes will also be reused soon to store "const Type_zone*"
pointers for the TIMESTAMP's "WITH TIME ZONE 'tz'" attribute
(a timestamp data type with a fixed time zone independent from @@time_zone).
The time zone attribute will be stored in exactly the same way like
a TYPELIB pointer is stored by ENUM/SET.
- Removing Column_definition_attributes members "interval" and "srid".
Deriving Column_definition_attributes from the generic attribute container
Type_extra_attributes instead.
- Adding a new class Type_typelib_attributes, to store
the TYPELIB of the ENUM and SET data types. Deriving Field_enum from it.
Removing the member Field_enum::typelib.
- Adding a new class Type_geom_attributes, to store
the GEOMETRY related attributes. Deriving Field_geom from it.
Removing the member Field_geom::srid.
- Removing virtual methods:
Field::get_typelib()
Type_all_attributes::get_typelib() and
Type_all_attributes::set_typelib()
They were very specific to TYPELIB.
Adding more generic virtual methods instead:
* Field::type_extra_attributes() - to get extra attributes
* Type_all_attributes::type_extra_attributes() - to get extra attributes
* Type_all_attributes::type_extra_attributes_addr() - to set extra attributes
- Removing Item_type_holder::enum_set_typelib. Deriving Item_type_holder
from the generic attribute container Type_extra_attributes instead.
This makes it possible for UNION to preserve SRID
(in addition to preserving TYPELIB).
- Deriving Item_hybrid_func from Type_extra_attributes.
This makes it possible for hybrid functions (e.g. CASE, COALESCE,
LEAST, GREATEST etc) to preserve SRID.
- Deriving Item_singlerow_subselect from Type_extra_attributes and
overriding methods:
* Item_cache::type_extra_attributes()
* subselect_single_select_engine::fix_length_and_dec()
* Item_singlerow_subselect::type_extra_attributes()
* Item_singlerow_subselect::type_extra_attributes_addr()
This is needed to preserve SRID in subqueries and TVCs
- Cleanup: fixing the data type of members
* Binlog_type_info::m_enum_typelib
* Binlog_type_info::m_set_typelib
from "TYPELIB *" to "const TYPELIB *"
This patch also fixes:
MDEV-33050 Build-in schemas like oracle_schema are accent insensitive
MDEV-33084 LASTVAL(t1) and LASTVAL(T1) do not work well with lower-case-table-names=0
MDEV-33085 Tables T1 and t1 do not work well with ENGINE=CSV and lower-case-table-names=0
MDEV-33086 SHOW OPEN TABLES IN DB1 -- is case insensitive with lower-case-table-names=0
MDEV-33088 Cannot create triggers in the database `MYSQL`
MDEV-33103 LOCK TABLE t1 AS t2 -- alias is not case sensitive with lower-case-table-names=0
MDEV-33109 DROP DATABASE MYSQL -- does not drop SP with lower-case-table-names=0
MDEV-33110 HANDLER commands are case insensitive with lower-case-table-names=0
MDEV-33119 User is case insensitive in INFORMATION_SCHEMA.VIEWS
MDEV-33120 System log table names are case insensitive with lower-cast-table-names=0
- Removing the virtual function strnncoll() from MY_COLLATION_HANDLER
- Adding a wrapper function CHARSET_INFO::streq(), to compare
two strings for equality. For now it calls strnncoll() internally.
In the future it will turn into a virtual function.
- Adding new accent sensitive case insensitive collations:
- utf8mb4_general1400_as_ci
- utf8mb3_general1400_as_ci
They implement accent sensitive case insensitive comparison.
The weight of a character is equal to the code point of its
upper case variant. These collations use Unicode-14.0.0 casefolding data.
The result of
my_charset_utf8mb3_general1400_as_ci.strcoll()
is very close to the former
my_charset_utf8mb3_general_ci.strcasecmp()
There is only a difference in a couple dozen rare characters, because:
- the switch from "tolower" to "toupper" comparison, to make
utf8mb3_general1400_as_ci closer to utf8mb3_general_ci
- the switch from Unicode-3.0.0 to Unicode-14.0.0
This difference should be tolarable. See the list of affected
characters in the MDEV description.
Note, utf8mb4_general1400_as_ci correctly handles non-BMP characters!
Unlike utf8mb4_general_ci, it does not treat all BMP characters
as equal.
- Adding classes representing names of the file based database objects:
Lex_ident_db
Lex_ident_table
Lex_ident_trigger
Their comparison collation depends on the underlying
file system case sensitivity and on --lower-case-table-names
and can be either my_charset_bin or my_charset_utf8mb3_general1400_as_ci.
- Adding classes representing names of other database objects,
whose names have case insensitive comparison style,
using my_charset_utf8mb3_general1400_as_ci:
Lex_ident_column
Lex_ident_sys_var
Lex_ident_user_var
Lex_ident_sp_var
Lex_ident_ps
Lex_ident_i_s_table
Lex_ident_window
Lex_ident_func
Lex_ident_partition
Lex_ident_with_element
Lex_ident_rpl_filter
Lex_ident_master_info
Lex_ident_host
Lex_ident_locale
Lex_ident_plugin
Lex_ident_engine
Lex_ident_server
Lex_ident_savepoint
Lex_ident_charset
engine_option_value::Name
- All the mentioned Lex_ident_xxx classes implement a method streq():
if (ident1.streq(ident2))
do_equal();
This method works as a wrapper for CHARSET_INFO::streq().
- Changing a lot of "LEX_CSTRING name" to "Lex_ident_xxx name"
in class members and in function/method parameters.
- Replacing all calls like
system_charset_info->coll->strcasecmp(ident1, ident2)
to
ident1.streq(ident2)
- Taking advantage of the c++11 user defined literal operator
for LEX_CSTRING (see m_strings.h) and Lex_ident_xxx (see lex_ident.h)
data types. Use example:
const Lex_ident_column primary_key_name= "PRIMARY"_Lex_ident_column;
is now a shorter version of:
const Lex_ident_column primary_key_name=
Lex_ident_column({STRING_WITH_LEN("PRIMARY")});
Ideally our methods and functions should do one thing, do that well,
and do only that. add_table_to_list does far more than adding a
table to a list, so this commit factors the TABLE_LIST creation out
to a new TABLE_LIST constructor. It then uses placement new()
to create it in the correct memory area (result of thd->calloc).
Benefits of this approach:
1. add_table_to_list now returns as early as possible on an error
2. fewer side-effects incurred on creating the TABLE_LIST object
3. TABLE_LIST won't be calloc'd if copy_to_db fails
4. local declarations moved closer to their respective first uses
5. improved code readability and logical flow
Also factored a couple of other functions to keep the happy path
more to the left, which makes them easier to follow at a glance.
Fixed that internal temporary tables are not waiting for freed disk space.
Other things:
- 'kill id' will now kill a query waiting for free disk space instantly.
Before it could take up to 60 seconds for the kill would be noticed.
- Fixed that sorting one index is not using MY_WAIT_IF_FULL for temp files.
- Fixed bug where share->write_flag set MY_WAIT_IF_FULL for temp files.
It is quite hard to do a test case for this. Instead I tested all
combinations interactively.
