Search Results
https://dev.mysql.com/doc/refman/9.7/en/replication-threads-monitor-worker.html
This system variable sets the maximum amount of memory (in bytes) available to applier worker thread queues holding events not yet applied. On a multithreaded replica, the Performance Schema tables replication_applier_status_by_coordinator and ...
https://dev.mysql.com/doc/refman/9.7/en/semijoins-antijoins.html
Each of these strategies can be enabled or disabled using the following optimizer_switch system variable flags: The semijoin flag controls whether semijoins and antijoins are used. A semijoin is a preparation-time transformation that enables ...
https://dev.mysql.com/doc/refman/9.7/en/source-thread-states.html
Set the terminology_use_previous system variable with session scope to support individual functions, or global scope to be a default for all new sessions. The following list shows the most common states you may see in the State column for the ...
https://dev.mysql.com/doc/refman/9.7/en/srjsapi-transactions.html
autocommit(): Get or set the value of the autocommit system variable: If session.autocommit() is called without a value, it returns the current value of autocommit; otherwise, it sets the value of autocommit. MLE supports a JavaScript MySQL ...
https://dev.mysql.com/doc/refman/9.7/en/stored-routines-js.html
JavaScript stored programs can be used together with other user-created and MySQL-native stored programs (subject to limitations described elsewhere in this section), as well as with MySQL system and user variables. For information about installing ...
https://dev.mysql.com/doc/refman/9.7/en/string-functions-charset.html
For operations that convert to character data, the character set and collation of the strings that result from the operations are defined by the character_set_connection and collation_connection system variables that determine the default connection ... MySQL has many operators and functions that return a ...
https://dev.mysql.com/doc/refman/9.7/en/subquery-materialization.html
For subquery materialization to be used in MySQL, the optimizer_switch system variable materialization flag must be enabled. The optimizer uses materialization to enable more efficient subquery processing. Materialization speeds up query execution ...
https://dev.mysql.com/doc/refman/9.7/en/subquery-optimization-with-exists.html
WHERE inner_expr=outer_expr) The subquery_materialization_cost_based flag of the optimizer_switch system variable enables control over the choice between subquery materialization and IN-to-EXISTS subquery transformation. Certain optimizations are ...
https://dev.mysql.com/doc/refman/9.7/en/sys-list-add.html
This function and list_drop() can be useful for manipulating the value of system variables such as sql_mode and optimizer_switch that take a comma-separated list of values. Adds a value to a comma-separated list of values and returns the result.
https://dev.mysql.com/doc/refman/9.7/en/update.html
UPDATE is a DML statement that modifies rows in a table. An UPDATE statement can start with a WITH clause to define common table expressions accessible within the UPDATE. Single-table syntax: UPDATE [LOW_PRIORITY] [IGNORE] table_reference SET ...