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https://dev.mysql.com/doc/refman/8.4/en/insert-on-duplicate.html
It is possible to use IGNORE with ON DUPLICATE KEY UPDATE in an INSERT statement, but this may not behave as you expect when inserting multiple rows into a table that has multiple unique keys. If you specify an ON DUPLICATE KEY UPDATE clause and a ...
https://dev.mysql.com/doc/refman/8.4/en/install-component.html
[SET variable = expr [, variable = expr] ...] variable: { {GLOBAL | @@GLOBAL.} [component_prefix.]system_var_name | {PERSIST | @@PERSIST.} [component_prefix.]system_var_name } This statement installs one or more components, which become active ...
https://dev.mysql.com/doc/refman/8.4/en/invisible-indexes.html
A table with no explicit primary key may still have an effective implicit primary key if it has any UNIQUE indexes on NOT NULL columns. MySQL supports invisible indexes; that is, indexes that are not used by the optimizer. The feature applies to ...
https://dev.mysql.com/doc/refman/8.4/en/keyring-encrypted-file-component.html
component_keyring_encrypted_file configuration files have these properties: A configuration file must be in valid JSON format. Any configuration file that stores a password should have a restrictive mode and be accessible only to the account used to ... Note component_keyring_encrypted_file is an extension included in MySQL Enterprise Edition, a commercial ...
https://dev.mysql.com/doc/refman/8.4/en/lock-order-tool.html
The primary variable is lock_order, which indicates whether to enable the LOCK_ORDER tool at runtime: If lock_order is disabled (the default), no other LOCK_ORDER system variables have any effect. If lock_order is disabled (the default), no other ...
https://dev.mysql.com/doc/refman/8.4/en/macos-installation-notes.html
Removing: After you have copied over the MySQL database files from the previous installation and have successfully started the new server, you should consider removing the old installation files to save disk space. You should keep the following ...
https://dev.mysql.com/doc/refman/8.4/en/manual-info.html
If you have questions about using MySQL, join the MySQL Community Slack. If you have suggestions concerning additions or corrections to the manual itself, please send them to the http://www.mysql.com/company/contact/. This is the Reference Manual ...
https://dev.mysql.com/doc/refman/8.4/en/memory-use.html
FLUSH TABLES does not return until all tables have been closed. MySQL allocates buffers and caches to improve performance of database operations. The default configuration is designed to permit a MySQL server to start on a virtual machine that has ...
https://dev.mysql.com/doc/refman/8.4/en/merge-table-advantages.html
You can even have many different MERGE tables that use overlapping sets of tables. (You must still specify the index definitions when you create a MERGE table, even though no indexes are created.) If you have a set of tables from which you create a ... MERGE tables can help you solve the following problems: Easily manage a set of log ...
https://dev.mysql.com/doc/refman/8.4/en/merge-table-problems.html
It is not possible to merge multiple MyISAM tables into a single MERGE table that would have more than this number of rows. As a workaround, use ALTER TABLE to ensure that all involved tables have the same PACK_KEYS value. The following are known ...