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https://dev.mysql.com/doc/refman/8.4/en/group-by-functional-dependence.html
The following discussion provides several examples of the ways in which MySQL detects functional dependencies. The examples use this notation: {X} -> {Y} Understand this as “X uniquely determines Y,” which also means that Y is functionally ...
https://dev.mysql.com/doc/refman/8.4/en/group-replication-monitoring.html
These Performance Schema tables display information specific to Group Replication: replication_group_member_stats: See Section 20.4.4, “The replication_group_member_stats Table”. These Performance Schema replication tables also show information ... You can use the MySQL Performance Schema to monitor Group ...
https://dev.mysql.com/doc/refman/8.4/en/help.html
Its proper operation requires that the help tables in the mysql database be initialized with help topic information (see Section 7.1.17, “Server-Side Help Support”). The HELP statement searches the help tables for the given search string and ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-online-ddl-failure-conditions.html
A timeout occurs while waiting for an exclusive lock on the table, which may be needed briefly during the initial and final phases of the DDL operation. The operation takes a long time and concurrent DML modifies the table so much that the size of ... The failure of an online DDL operation is typically due to one of the following conditions: An ALGORITHM clause specifies an algorithm that is not compatible with the particular type of DDL operation or storage ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-performance-midpoint_insertion.html
The goal is to make sure that frequently accessed (“hot”) pages remain in the buffer pool, even as read-ahead and full table scans bring in new blocks that might or might not be accessed afterward. You can control the insertion point in the LRU ... Rather than using a strict LRU algorithm, InnoDB uses a technique to minimize the amount of data that is brought into the buffer pool and never accessed ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-troubleshooting.html
If the problem is with table creation, tablespaces, or data dictionary operations, refer to the InnoDB Information Schema system tables to examine contents of the InnoDB internal data dictionary. The following general guidelines apply to ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-undo-tablespaces.html
Undo tablespaces contain undo logs, which are collections of records containing information about how to undo the latest change by a transaction to a clustered index record. Default undo tablespaces are created at initialization time to provide a ...To handle aggressive growth, the file extension size is doubled if the previous file extension happened less than 0.1 seconds ...
https://dev.mysql.com/doc/refman/8.4/en/install-component.html
INSTALL COMPONENT requires the INSERT privilege for the mysql.component system table because it adds a row to that table to register the component. Specifying PERSIST for any variable in SET silently executes SET PERSIST_ONLY immediately after ...
https://dev.mysql.com/doc/refman/8.4/en/json-validation-functions.html
As before, you can see this by attempting to insert the value into the geo table, then issuing SHOW WARNINGS afterwards: mysql> INSERT INTO geo VALUES(@point3); ERROR 3819 (HY000): Check constraint 'geo_chk_1' is violated. MySQL supports validation ...
https://dev.mysql.com/doc/refman/8.4/en/key-space.html
This is for the worst case when all keys are inserted in sorted order and the table doesn't have any compressed keys. In MyISAM tables, you can also prefix compress numbers by specifying the PACK_KEYS=1 table option when you create the table. You ...