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https://dev.mysql.com/doc/refman/8.0/en/subquery-optimization.html
Note A limitation on UPDATE and DELETE statements that use a subquery to modify a single table is that the optimizer does not use semijoin or materialization subquery optimizations. As a workaround, try rewriting them as multiple-table UPDATE and ...
https://dev.mysql.com/doc/refman/8.0/en/sys-schema-progress-reporting.html
The following sys schema views provide progress reporting for long-running transactions: processlist session x$processlist x$session Assuming that the required instruments and consumers are enabled, the progress column of these views shows the ...
https://dev.mysql.com/doc/refman/8.0/en/alter-user.html
ALTER USER [IF EXISTS] user [auth_option] [, user [auth_option]] ... [REQUIRE {NONE | tls_option [[AND] tls_option] ...}] [WITH resource_option [resource_option] ...] [password_option | lock_option] ... It enables authentication, role, SSL/TLS, ...
https://dev.mysql.com/doc/refman/8.0/en/table-locking.html
For storage engines that use only table-level locking (such as MyISAM, MEMORY, and MERGE), this gives all statements that update (modify) a table lower priority than SELECT statements. InnoDB tables use row-level locking so that multiple sessions ...
https://dev.mysql.com/doc/refman/8.0/en/temporary-table-problems.html
Temporary tables created with CREATE TEMPORARY TABLE have the following limitations: TEMPORARY tables are supported only by the InnoDB, MEMORY, MyISAM, and MERGE storage engines. Use ALTER TABLE instead: ALTER TABLE old_name RENAME new_name; You ...
https://dev.mysql.com/doc/refman/8.0/en/aggregate-functions.html
This section describes aggregate functions that operate on sets of values. They are often used with a GROUP BY clause to group values into subsets. If you use an aggregate function in a statement containing no GROUP BY clause, it is equivalent to ...
https://dev.mysql.com/doc/refman/8.0/en/where-optimization.html
HAVING is merged with WHERE if you do not use GROUP BY or aggregate functions (COUNT(), MIN(), and so on). This section discusses optimizations that can be made for processing WHERE clauses. The examples use SELECT statements, but the same ...
https://dev.mysql.com/doc/refman/8.0/en/with.html
Common Table Expressions Recursive Common Table Expressions Limiting Common Table Expression Recursion Recursive Common Table Expression Examples Common Table Expressions Compared to Similar Constructs For information about CTE optimization, see ...
https://dev.mysql.com/doc/refman/8.0/en/converting-tables-to-innodb.html
For inserts, InnoDB uses the insert buffer to merge secondary index records to indexes in batches. If you have MyISAM tables that you want to convert to InnoDB for better reliability and scalability, review the following guidelines and tips before ...
https://dev.mysql.com/doc/refman/8.0/en/flush.html
| tables_option } flush_option: { BINARY LOGS | ENGINE LOGS | ERROR LOGS | GENERAL LOGS | HOSTS | LOGS | PRIVILEGES | OPTIMIZER_COSTS | RELAY LOGS [FOR CHANNEL channel] | SLOW LOGS | STATUS | USER_RESOURCES } tables_option: { table_synonym | ...