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https://dev.mysql.com/doc/refman/8.4/en/cannot-roll-back.html
In general, these include data definition language (DDL) statements, such as those that create or drop databases, those that create, drop, or alter tables or stored routines. If you issue a statement early in a transaction that cannot be rolled ...
https://dev.mysql.com/doc/refman/8.4/en/create-event.html
The minimum requirements for a valid CREATE EVENT statement are as follows: The keywords CREATE EVENT plus an event name, which uniquely identifies the event in a database schema. CREATE [DEFINER = user] EVENT [IF NOT EXISTS] event_name ON SCHEDULE ...
https://dev.mysql.com/doc/refman/8.4/en/create-trigger.html
A trigger is a named database object that is associated with a table, and that activates when a particular event occurs for the table. DROP TABLE and TRUNCATE TABLE statements on the table do not activate this trigger, because they do not use DELETE. CREATE [DEFINER = user] TRIGGER [IF NOT EXISTS] trigger_name trigger_time trigger_event ON tbl_name FOR EACH ROW [trigger_order] trigger_body trigger_time: { BEFORE | AFTER } trigger_event: { INSERT | UPDATE | DELETE } trigger_order: { FOLLOWS | PRECEDES } other_trigger_name This statement creates a new ...
https://dev.mysql.com/doc/refman/8.4/en/memory-storage-engine.html
To free all the memory used by a MEMORY table when you no longer require its contents, execute DELETE or TRUNCATE TABLE to remove all rows, or remove the table altogether using DROP TABLE. The MEMORY storage engine (formerly known as HEAP) creates ...
https://dev.mysql.com/doc/refman/8.4/en/memory-use.html
MySQL allocates buffers and caches to improve performance of database operations. This memory is not released by the corresponding REVOKE, DROP USER, DROP SERVER, and UNINSTALL PLUGIN statements, so for a server that executes many instances of the ...The default configuration is designed to permit a MySQL server to start on a virtual machine that has approximately 512MB of ...
https://dev.mysql.com/doc/refman/8.4/en/metadata-locking.html
MySQL uses metadata locking to manage concurrent access to database objects and to ensure data consistency. For example, a second session blocks if it attempts any of these operations: DROP TABLE t; ALTER TABLE t ...; DROP TABLE nt; ALTER TABLE nt ...Metadata locking applies not just to tables, but also to schemas, stored programs (procedures, functions, triggers, scheduled events), tablespaces, user locks acquired with the GET_LOCK() function (see Section 14.14, “Locking Functions”), and locks acquired with the locking service described in Section 7.6.9.1, “The Locking ...
https://dev.mysql.com/doc/refman/8.4/en/session-state-tracking.html
The following characteristics are relevant for this purpose: READ ONLY READ WRITE ISOLATION LEVEL WITH CONSISTENT SNAPSHOT Available Session State Trackers To support the session-tracking activities, notification is available for these types of ...A ...
https://dev.mysql.com/doc/refman/8.4/en/show-grants.html
SHOW GRANTS [FOR user_or_role [USING role [, role] ...]] user_or_role: { user (see Section 8.2.4, “Specifying Account Names”) | role (see Section 8.2.5, “Specifying Role Names”. } This statement displays the privileges and roles that are ...
https://dev.mysql.com/doc/refman/8.4/en/upgrading-what-is-upgraded.html
mysql schema tables fall into two broad categories: Data dictionary tables, which store database object metadata. Placing the host name and user name together means that index lookup can be used, which improves performance for CREATE USER, DROP ...
https://dev.mysql.com/doc/relnotes/mysql/8.4/en/news-8-4-5.html
If one client session had a uncommitted transaction that caused a DROP TABLE statement in another client session to be blocked, a third client session hung when trying to issue a USE DATABASE statement. (Bug #37570206) Audit Log Notes ...