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https://dev.mysql.com/doc/refman/8.4/en/optimizer-issues.html
Use ANALYZE TABLE tbl_name to update the key distributions for the scanned table. Use FORCE INDEX for the scanned table to tell MySQL that table scans are very expensive compared to using the given index: SELECT * FROM t1, t2 FORCE INDEX ... MySQL ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-functions.html
The units indicator depends on the size of the byte-count argument as shown in the following table. The units indicator depends on the size of the time-value argument as shown in the following table. The thread ID return value is a value of the type ... MySQL includes built-in SQL functions that format or retrieve Performance Schema data, and that may be used as equivalents for the corresponding sys schema stored ...
https://dev.mysql.com/doc/refman/8.4/en/replication-features-variables.html
sql_mode is also replicated except for the NO_DIR_IN_CREATE mode; the replica always preserves its own value for NO_DIR_IN_CREATE, regardless of changes to it on the source. However, when mysqlbinlog parses a SET @@sql_mode = mode statement, the ...
https://dev.mysql.com/doc/refman/8.4/en/replication-mode-change-online-concepts.html
When using GTIDs you can take advantage of GTID auto-positioning and automatic failover, and use WAIT_FOR_EXECUTED_GTID_SET(), session_track_gtids, and Performance Schema tables to monitor replicated transactions (see Section 29.12.11, ... Before ...
https://dev.mysql.com/doc/refman/8.4/en/selecting-all.html
Fix only the erroneous record with an UPDATE statement: mysql> UPDATE pet SET birth = '1989-08-31' WHERE name = 'Bowser'; The UPDATE changes only the record in question and does not require you to reload the table. If a table contains invisible ...
https://dev.mysql.com/doc/refman/8.4/en/show-engines.html
row *************************** Engine: MEMORY Support: YES Comment: Hash based, stored in memory, useful for temporary tables Transactions: NO XA: NO Savepoints: NO *************************** 2. row *************************** Engine: MRG_MYISAM ... SHOW [STORAGE] ENGINES SHOW ENGINES displays status information about the server's storage ...
https://dev.mysql.com/doc/refman/8.4/en/stop-replica.html
When the source is using the row-based binary logging format, you should execute STOP REPLICA or STOP REPLICA SQL_THREAD on the replica prior to shutting down the replica server if you are replicating any tables that use a nontransactional storage ...] thread_type: IO_THREAD | SQL_THREAD channel_option: FOR CHANNEL channel Stops the replication ...
https://dev.mysql.com/doc/refman/8.4/en/testing-server.html
For more information about mysql, mysqladmin, and mysqlshow, see Section 6.5.1, “mysql — The MySQL Command-Line Client”, Section 6.5.2, “mysqladmin — A MySQL Server Administration Program”, and Section 6.5.6, “mysqlshow — Display ...
https://dev.mysql.com/doc/refman/8.4/en/xa-restrictions.html
The implementation of internal XA requires that a storage engine support two-phase commit at the table handler level, and currently this is true only for InnoDB. This means that the same XA transaction can appear in the events_transactions_current ... XA transaction support is limited to the InnoDB storage ...
https://dev.mysql.com/doc/c-api/8.4/en/c-api-prepared-statement-type-codes.html
The following table shows the permissible values for the buffer_type member of MYSQL_BIND structures for input values sent to the server. The table shows the C variable types that you can use, the corresponding type codes, and the SQL data types for ... The buffer_type member of MYSQL_BIND structures indicates the data type of the C language variable bound to a statement parameter or result set ...