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https://dev.mysql.com/doc/refman/8.4/en/condition-filtering.html
In join processing, prefix rows are those rows passed from one table in a join to the next. In general, the optimizer attempts to put tables with low prefix counts early in the join order to keep the number of row combinations from increasing ...
https://dev.mysql.com/doc/refman/8.4/en/create-logfile-group.html
CREATE LOGFILE GROUP logfile_group ADD UNDOFILE 'undo_file' [INITIAL_SIZE [=] initial_size] [UNDO_BUFFER_SIZE [=] undo_buffer_size] [REDO_BUFFER_SIZE [=] redo_buffer_size] [NODEGROUP [=] nodegroup_id] [WAIT] [COMMENT [=] 'string'] ENGINE [=] ...
https://dev.mysql.com/doc/refman/8.4/en/create-table-foreign-keys.html
Example queries are show here: mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_FOREIGN \G *************************** 1. MySQL supports foreign keys, which permit cross-referencing related data across tables, and foreign key constraints, which help ...
https://dev.mysql.com/doc/refman/8.4/en/declare-handler.html
statement handler_action: { CONTINUE | EXIT | UNDO } condition_value: { mysql_error_code | SQLSTATE [VALUE] sqlstate_value | condition_name | SQLWARNING | NOT FOUND | SQLEXCEPTION } The DECLARE ... HANDLER statement specifies a handler that deals ...
https://dev.mysql.com/doc/refman/8.4/en/diagnostics-area.html
SQL statements produce diagnostic information that populates the diagnostics area. Standard SQL has a diagnostics area stack, containing a diagnostics area for each nested execution context. Standard SQL also supports GET STACKED DIAGNOSTICS syntax ...
https://dev.mysql.com/doc/refman/8.4/en/error-log-configuration.html
In MySQL 8.4, error logging uses the MySQL component architecture described at Section 7.5, “MySQL Components”. The error log subsystem consists of components that perform log event filtering and writing, as well as a system variable that ...
https://dev.mysql.com/doc/refman/8.4/en/explain-for-connection.html
To obtain the execution plan for an explainable statement executing in a named connection, use this statement: EXPLAIN [options] FOR CONNECTION connection_id; EXPLAIN FOR CONNECTION returns the EXPLAIN information that is currently being used to ...
https://dev.mysql.com/doc/refman/8.4/en/extensions-to-ansi.html
This gives better performance for some very specific, but quite normal queries. MySQL Server supports some extensions that you are not likely to find in other SQL DBMSs. Be warned that if you use them, your code is most likely not portable to other ...
https://dev.mysql.com/doc/refman/8.4/en/features.html
Statements and Functions Full operator and function support in the SELECT list and WHERE clause of queries. This section describes some of the important characteristics of the MySQL Database Software. In most respects, the roadmap applies to all ...
https://dev.mysql.com/doc/refman/8.4/en/federated-usagenotes.html
Queries that fail to use indexes can thus cause poor performance and network overload. The following items indicate features that the FEDERATED storage engine does and does not support: The remote server must be a MySQL server. The remote table that ...