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727491b72a
This includes all test changes from
"Changing all cost calculation to be given in milliseconds"
and forwards.
Some of the things that caused changes in the result files:
- As part of fixing tests, I added 'echo' to some comments to be able to
easier find out where things where wrong.
- MATERIALIZED has now a higher cost compared to X than before. Because
of this some MATERIALIZED types have changed to DEPENDEND SUBQUERY.
- Some test cases that required MATERIALIZED to repeat a bug was
changed by adding more rows to force MATERIALIZED to happen.
- 'Filtered' in SHOW EXPLAIN has in many case changed from 100.00 to
something smaller. This is because now filtered also takes into
account the smallest possible ref access and filters, even if they
where not used. Another reason for 'Filtered' being smaller is that
we now also take into account implicit filtering done for subqueries
using FIRSTMATCH.
(main.subselect_no_exists_to_in)
This is caluculated in best_access_path() and stored in records_out.
- Table orders has changed because more accurate costs.
- 'index' and 'ALL' for small tables has changed to use 'range' or
'ref' because of optimizer_scan_setup_cost.
- index can be changed to 'range' as 'range' optimizer assumes we don't
have to read the blocks from disk that range optimizer has already read.
This can be confusing in the case where there is no obvious where clause
but instead there is a hidden 'key_column > NULL' added by the optimizer.
(main.subselect_no_exists_to_in)
- Scan on primary clustered key does not report 'Using Index' anymore
(It's a table scan, not an index scan).
- For derived tables, the number of rows is now 100 instead of 2,
which can be seen in EXPLAIN.
- More tests have "Using index for group by" as the cost of this
optimization is now more correct (lower).
- A primary key could be preferred for a normal key, even if it would
access more rows, as it's faster to do 1 lokoup and 3 'index_next' on a
clustered primary key than one lookup trough a secondary.
(main.stat_tables_innodb)
Notes:
- There was a 4.7% more calls to best_extension_by_limited_search() in
the main.greedy_optimizer test. However examining the test results
it looked that the plans where slightly better (eq_ref where more
chained together) so I assume this is ok.
- I have verified a few test cases where there was notable/unexpected
changes in the plan and in all cases the new optimizer plans where
faster. (main.greedy_optimizer and some others)
125 lines
3.5 KiB
Text
125 lines
3.5 KiB
Text
#
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# Bug#18925: subqueries with MIN/MAX functions on INFORMATION_SCHEMA
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#
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SELECT t.table_name, c1.column_name
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FROM information_schema.tables t
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INNER JOIN
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information_schema.columns c1
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ON t.table_schema = c1.table_schema AND
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t.table_name = c1.table_name
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WHERE t.table_schema = 'information_schema' AND
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c1.ordinal_position =
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( SELECT COALESCE(MIN(c2.ordinal_position),1)
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FROM information_schema.columns c2
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WHERE c2.table_schema = t.table_schema AND
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c2.table_name = t.table_name AND
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c2.column_name LIKE '%SCHEMA%'
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)
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AND t.table_name NOT LIKE 'innodb%' and t.table_name NOT LIKE "OPTIMIZER_TRACE%";
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table_name column_name
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ALL_PLUGINS PLUGIN_NAME
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APPLICABLE_ROLES GRANTEE
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CHARACTER_SETS CHARACTER_SET_NAME
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CHECK_CONSTRAINTS CONSTRAINT_SCHEMA
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CLIENT_STATISTICS CLIENT
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COLLATIONS COLLATION_NAME
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COLLATION_CHARACTER_SET_APPLICABILITY COLLATION_NAME
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COLUMNS TABLE_SCHEMA
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COLUMN_PRIVILEGES TABLE_SCHEMA
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ENABLED_ROLES ROLE_NAME
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ENGINES ENGINE
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EVENTS EVENT_SCHEMA
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FILES TABLE_SCHEMA
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GEOMETRY_COLUMNS F_TABLE_SCHEMA
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GLOBAL_STATUS VARIABLE_NAME
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GLOBAL_VARIABLES VARIABLE_NAME
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INDEX_STATISTICS TABLE_SCHEMA
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KEYWORDS WORD
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KEY_CACHES KEY_CACHE_NAME
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KEY_COLUMN_USAGE CONSTRAINT_SCHEMA
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OPTIMIZER_COSTS ENGINE
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PARAMETERS SPECIFIC_SCHEMA
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PARTITIONS TABLE_SCHEMA
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PLUGINS PLUGIN_NAME
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PROCESSLIST ID
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PROFILING QUERY_ID
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REFERENTIAL_CONSTRAINTS CONSTRAINT_SCHEMA
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ROUTINES ROUTINE_SCHEMA
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SCHEMATA SCHEMA_NAME
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SCHEMA_PRIVILEGES TABLE_SCHEMA
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SESSION_STATUS VARIABLE_NAME
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SESSION_VARIABLES VARIABLE_NAME
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SPATIAL_REF_SYS SRID
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SQL_FUNCTIONS FUNCTION
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STATISTICS TABLE_SCHEMA
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SYSTEM_VARIABLES VARIABLE_NAME
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TABLES TABLE_SCHEMA
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TABLESPACES TABLESPACE_NAME
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TABLE_CONSTRAINTS CONSTRAINT_SCHEMA
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TABLE_PRIVILEGES TABLE_SCHEMA
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TABLE_STATISTICS TABLE_SCHEMA
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TRIGGERS TRIGGER_SCHEMA
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USER_PRIVILEGES GRANTEE
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USER_STATISTICS USER
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VIEWS TABLE_SCHEMA
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SELECT t.table_name, c1.column_name
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FROM information_schema.tables t
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INNER JOIN
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information_schema.columns c1
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ON t.table_schema = c1.table_schema AND
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t.table_name = c1.table_name
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WHERE t.table_schema = 'information_schema' AND
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c1.ordinal_position =
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( SELECT COALESCE(MIN(c2.ordinal_position),1)
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FROM information_schema.columns c2
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WHERE c2.table_schema = 'information_schema' AND
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c2.table_name = t.table_name AND
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c2.column_name LIKE '%SCHEMA%'
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)
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AND t.table_name NOT LIKE 'innodb%' and t.table_name NOT LIKE "OPTIMIZER_TRACE%";
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table_name column_name
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ALL_PLUGINS PLUGIN_NAME
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APPLICABLE_ROLES GRANTEE
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CHARACTER_SETS CHARACTER_SET_NAME
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CHECK_CONSTRAINTS CONSTRAINT_SCHEMA
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CLIENT_STATISTICS CLIENT
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COLLATIONS COLLATION_NAME
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COLLATION_CHARACTER_SET_APPLICABILITY COLLATION_NAME
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COLUMNS TABLE_SCHEMA
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COLUMN_PRIVILEGES TABLE_SCHEMA
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ENABLED_ROLES ROLE_NAME
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ENGINES ENGINE
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EVENTS EVENT_SCHEMA
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FILES TABLE_SCHEMA
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GEOMETRY_COLUMNS F_TABLE_SCHEMA
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GLOBAL_STATUS VARIABLE_NAME
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GLOBAL_VARIABLES VARIABLE_NAME
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INDEX_STATISTICS TABLE_SCHEMA
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KEYWORDS WORD
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KEY_CACHES KEY_CACHE_NAME
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KEY_COLUMN_USAGE CONSTRAINT_SCHEMA
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OPTIMIZER_COSTS ENGINE
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PARAMETERS SPECIFIC_SCHEMA
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PARTITIONS TABLE_SCHEMA
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PLUGINS PLUGIN_NAME
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PROCESSLIST ID
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PROFILING QUERY_ID
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REFERENTIAL_CONSTRAINTS CONSTRAINT_SCHEMA
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ROUTINES ROUTINE_SCHEMA
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SCHEMATA SCHEMA_NAME
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SCHEMA_PRIVILEGES TABLE_SCHEMA
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SESSION_STATUS VARIABLE_NAME
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SESSION_VARIABLES VARIABLE_NAME
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SPATIAL_REF_SYS SRID
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SQL_FUNCTIONS FUNCTION
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STATISTICS TABLE_SCHEMA
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SYSTEM_VARIABLES VARIABLE_NAME
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TABLES TABLE_SCHEMA
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TABLESPACES TABLESPACE_NAME
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TABLE_CONSTRAINTS CONSTRAINT_SCHEMA
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TABLE_PRIVILEGES TABLE_SCHEMA
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TABLE_STATISTICS TABLE_SCHEMA
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TRIGGERS TRIGGER_SCHEMA
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USER_PRIVILEGES GRANTEE
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USER_STATISTICS USER
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VIEWS TABLE_SCHEMA
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