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https://dev.mysql.com/doc/refman/8.4/en/online-ddl-parallel-thread-configuration.html
The default setting is calculated by the number of available logical processors on the system divided by 8, with a minimum default value of 4. The maximum setting is 256, which is the maximum number for all sessions. The actual number of threads ...
https://dev.mysql.com/doc/refman/8.4/en/optimizer-hints.html
To create these names, use the QB_NAME hint, which assigns a name to the query block in which it occurs: QB_NAME(name) QB_NAME hints can be used to make explicit in a clear way which query blocks other hints apply to. One means of control over ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-innodb-storage-layout.html
(See Section 17.6.2.1, “Clustered and Secondary Indexes”.) Create an AUTO_INCREMENT column as the primary key if your primary key is long, or index a prefix of a long VARCHAR column instead of the entire column. Once your data reaches a stable ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-memory-tables.html
On the CREATE INDEX statement, use the clause USING BTREE or USING HASH. Consider using MEMORY tables for noncritical data that is accessed often, and is read-only or rarely updated. Benchmark your application against equivalent InnoDB or MyISAM ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-queries-myisam.html
Some general tips for speeding up queries on MyISAM tables: To help MySQL better optimize queries, use ANALYZE TABLE or run myisamchk --analyze on a table after it has been loaded with data. This updates a value for each index part that indicates ...
https://dev.mysql.com/doc/refman/8.4/en/out-of-range-and-overflow.html
If no restrictive modes are enabled, MySQL clips the value to the appropriate endpoint of the column data type range and stores the resulting value instead. When an out-of-range value is assigned to an integer column, MySQL stores the value ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-clone-tables.html
If the clone plugin is loaded but disabled, the tables are not created. The following sections describe the Performance Schema tables associated with the clone plugin (see Section 7.6.7, “The Clone Plugin”). clone_status: status information ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-instrument-naming.html
Example names: wait/io/file/myisam/log wait/io/file/mysys/charset wait/lock/table/sql/handler wait/synch/cond/mysys/COND_alarm wait/synch/cond/sql/BINLOG::update_cond wait/synch/mutex/mysys/BITMAP_mutex wait/synch/mutex/sql/LOCK_delete ... An ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-miscellaneous-tables.html
user_defined_functions: Loadable functions registered by a component, plugin, or CREATE FUNCTION statement. The following sections describe tables that do not fall into the table categories discussed in the preceding sections: ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-ndb-sync-excluded-objects-table.html
This table provides information about NDB database objects which cannot be automatically synchronized between NDB Cluster's dictionary and the MySQL data dictionary. Example information about NDB database objects which cannot be synchronized with ...