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https://dev.mysql.com/doc/refman/8.4/en/string-comparison-functions.html
For example, consider the following table and data: CREATE TABLE foo (bar VARCHAR(10)); INSERT INTO foo VALUES (NULL), (NULL); The query SELECT COUNT(*) FROM foo WHERE bar LIKE '%baz%'; returns 0. Table 14.13 String Comparison Functions and ...
https://dev.mysql.com/doc/refman/8.4/en/sys-ps-setup-reset-to-default.html
row *************************** status: Resetting: setup_actors INSERT IGNORE INTO performance_schema.setup_actors VALUES ('%', '%', '%') ... Parameters in_verbose BOOLEAN: Whether to display information about each setup stage during procedure ...
https://dev.mysql.com/doc/refman/8.4/en/sys-sys-config.html
To enable debug output without having to set that variable in individual sessions, add the option to the table: mysql> INSERT INTO sys.sys_config (variable, value) VALUES('debug', 'ON'); To change the debug setting in the table, do two things. This ...
https://dev.mysql.com/doc/refman/8.4/en/time.html
In particular, any fractional part in a value inserted into a TIME column is stored rather than discarded. MySQL retrieves and displays TIME values in 'hh:mm:ss' format (or 'hhh:mm:ss' format for large hours values). The hours part may be so large ...
https://dev.mysql.com/doc/refman/8.4/en/type-conversion.html
When an operator is used with operands of different types, type conversion occurs to make the operands compatible. For example, MySQL automatically converts strings to numbers as necessary, and vice versa. mysql> SELECT 1+'1'; -> 2 mysql> SELECT ...
https://dev.mysql.com/doc/refman/8.4/en/view-restrictions.html
Dump files created with mysqldump cannot be loaded into servers that enforce the column-length restriction. The maximum number of tables that can be referenced in the definition of a view is 61. View processing is not optimized: It is not possible ...
https://dev.mysql.com/doc/refman/8.4/en/view-syntax.html
The CREATE VIEW statement creates a new view (see Section 15.1.23, “CREATE VIEW Statement”). To alter the definition of a view or drop a view, use ALTER VIEW (see Section 15.1.11, “ALTER VIEW Statement”), or DROP VIEW (see Section 15.1.35, ...
https://dev.mysql.com/doc/mysql-enterprise-backup/8.4/en/backup-performance.html
MyISAM Considerations Important Although mysqlbackup backs up InnoDB tables without interrupting database use, the final stage that copies non-InnoDB files (such as MyISAM tables and .sdi files) temporarily puts those tables into a read-only state, ... This section describes the performance considerations for backing up a database with MySQL Enterprise ...
https://dev.mysql.com/doc/mysql-cluster-manager/8.4/en/mcm-rotate-log.html
rotate log [{--hosts=|-h }host_list] [site_name] host_list: host[,host[,...]] Rotate mcmd logs for the connected MySQL Cluster Manager agent, for agents running on certain hosts, or for agents on all hosts in a management site.
https://dev.mysql.com/doc/mysql-cluster-manager/8.4/en/mcm-using-mcmd.html
You can comment out a line by inserting a leading hash character (#). This is useful when an agent has fallen into an inconsistent state and cannot be properly restarted. Invoking this executable starts the MySQL Cluster Manager Agent, to which you ...