https://dev.mysql.com/statement-summary-tables.html
(The DIGEST_TEXT column contains the corresponding normalized statement digest text, but is neither a grouping nor a summary column. The QUERY_SAMPLE_TEXT, QUERY_SAMPLE_SEEN, and QUERY_SAMPLE_TIMER_WAIT columns also are neither grouping nor summary ... The Performance Schema maintains tables for collecting current and recent statement events, and aggregates that information in summary ...
https://dev.mysql.com/statistics-table.html
However, prefix lengths for index specifications in CREATE TABLE, ALTER TABLE, and CREATE INDEX statements are interpreted as number of characters for nonbinary string types (CHAR, VARCHAR, TEXT) and number of bytes for binary string types (BINARY, ...The information_schema_stats_expiry system variable defines the period of time before cached table statistics ...
https://dev.mysql.com/string-types.html
The string data types are CHAR, VARCHAR, BINARY, VARBINARY, BLOB, TEXT, ENUM, and SET. For information about storage requirements of the string data types, see Section 11.7, “Data Type Storage Requirements”. For descriptions of functions that ...
https://dev.mysql.com/subquery-materialization.html
For extended EXPLAIN output, the text displayed by a following SHOW WARNINGS includes materialize and materialized-subquery. The optimizer uses materialization to enable more efficient subquery processing. Materialization speeds up query execution ...
https://dev.mysql.com/sys-ps-thread-account.html
Given a Performance Schema thread ID, returns the user_name@host_name account associated with the thread. in_thread_id BIGINT UNSIGNED: The thread ID for which to return the account. The value should match the THREAD_ID column from some Performance ...
https://dev.mysql.com/table-size-limit.html
ALTER TABLE tbl_name MAX_ROWS=1000000000 AVG_ROW_LENGTH=nnn; You have to specify AVG_ROW_LENGTH only for tables with BLOB or TEXT columns; in this case, MySQL cannot optimize the space required based only on the number of rows. The effective ...
https://dev.mysql.com/thread-information.html
Info contains the text of the statement being executed by the thread, or NULL if it is not executing one. When you are attempting to ascertain what your MySQL server is doing, it can be helpful to examine the process list, which is the set of ...
https://dev.mysql.com/triggers-table.html
To see information about a table's triggers, you must have the TRIGGER privilege for the table. The TRIGGERS table has these columns: TRIGGER_CATALOG The name of the catalog to which the trigger belongs. TRIGGER_SCHEMA The name of the schema ...
https://dev.mysql.com/uninstall-plugin.html
For example, if a full-text parser plugin is associated with a FULLTEXT index on the table, uninstalling the plugin makes the table unusable. UNINSTALL PLUGIN plugin_name This statement removes an installed server plugin. plugin_name must be the ...
https://dev.mysql.com/using-log-files.html
If you find the text mysqld restarted in the error log (normally a file named host_name.err) you probably have found a query that causes mysqld to fail. Note that before starting mysqld with the general query log enabled, you should check all your ...
