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https://dev.mysql.com/doc/refman/8.4/en/innodb-online-ddl-single-multi.html
Operations all using the same specific LOCK clause, that you want to either succeed or fail as a group. Before the introduction of online DDL, it was common practice to combine many DDL operations into a single ALTER TABLE statement. Because each ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-performance-ro-txn.html
InnoDB can avoid the overhead associated with setting up the transaction ID (TRX_ID field) for transactions that are known to be read-only. A transaction ID is only needed for a transaction that might perform write operations or locking reads such ...
https://dev.mysql.com/doc/refman/8.4/en/json-search-functions.html
This includes (but is not limited to) SELECT lists, WHERE and HAVING clauses, and ORDER BY and GROUP BY clauses. The functions in this section perform search or comparison operations on JSON values to extract data from them, report whether data ...
https://dev.mysql.com/doc/refman/8.4/en/json.html
ORDER BY and GROUP BY for JSON values works according to these principles: Ordering of scalar JSON values uses the same rules as in the preceding discussion. Non-NULL values are converted to a numeric type and aggregated, except for MIN(), MAX(), ...
https://dev.mysql.com/doc/refman/8.4/en/kill.html
In most cases, it might take some time for the thread to die because the kill flag is checked only at specific intervals: During SELECT operations, for ORDER BY and GROUP BY loops, the flag is checked after reading a block of rows. KILL [CONNECTION ...
https://dev.mysql.com/doc/refman/8.4/en/known-issues.html
DISTINCT with ORDER BY does not work inside GROUP_CONCAT() if you do not use all and only those columns that are in the DISTINCT list. This means that values cannot reliably be used in GROUP BY, ORDER BY, or DISTINCT if they differ only after the ...
https://dev.mysql.com/doc/refman/8.4/en/locale-support.html
The lc_time_names value does not affect the result from FORMAT(), but this function takes an optional third parameter that enables a locale to be specified to be used for the result number's decimal point, thousands separator, and grouping between ... The locale indicated by the lc_time_names system variable controls the language used to display day and month names and ...
https://dev.mysql.com/doc/refman/8.4/en/mathematical-functions.html
Use of a column with RAND() values in an ORDER BY or GROUP BY clause may yield unexpected results because for either clause a RAND() expression can be evaluated multiple times for the same row, each time returning a different result. ABS(X) Returns ...
https://dev.mysql.com/doc/refman/8.4/en/memory-storage-engine.html
The MEMORY storage engine (formerly known as HEAP) creates special-purpose tables with contents that are stored in memory. Because the data is vulnerable to crashes, hardware issues, or power outages, only use these tables as temporary work areas ...
https://dev.mysql.com/doc/refman/8.4/en/merge-storage-engine.html
The MERGE storage engine, also known as the MRG_MyISAM engine, is a collection of identical MyISAM tables that can be used as one. “Identical” means that all tables have identical column data types and index information. You cannot merge MyISAM ...