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https://dev.mysql.com/doc/refman/8.4/en/optimizer-issues.html
MySQL uses a cost-based optimizer to determine the best way to resolve a query. For example, start mysqld with the --max-seeks-for-key=1000 option or use SET max_seeks_for_key=1000 to tell the optimizer to assume that no key scan causes more than ...In many cases, MySQL can calculate the best possible query plan, but sometimes MySQL does not have enough information about the data at hand and has to make “educated” guesses about the ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-innodb-configuration-variables.html
Because the InnoDB storage engine performs many of its optimizations automatically, many performance-tuning tasks involve monitoring to ensure that the database is performing well, and changing configuration options when performance drops.
https://dev.mysql.com/doc/refman/8.4/en/optimizing-innodb-logging.html
Consider the following guidelines for optimizing redo logging: Increase the size of your redo log files. Optimize the use of spin delay by user threads waiting for flushed redo. When InnoDB has written redo log files full, it must write the ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-subqueries.html
Development is ongoing, so no optimization tip is reliable for the long term. See also Section 10.2.2, “Optimizing Subqueries, Derived Tables, View References, and Common Table Expressions”. The following list provides some interesting tricks ...
https://dev.mysql.com/doc/internals/en/optimizer-joins.html
This section discusses the various methods used to optimize joins.
https://dev.mysql.com/doc/internals/en/optimizer-partitioning-related.html
See Partitioning for general information about the partitioning implementation in MySQL 5.1 and later.
https://dev.mysql.com/doc/internals/en/optimizer-tracing.html
In MySQL 5.6, a new tracing capability was added to the MySQL optimizer. The interface is provided by a set of optimizer_trace_xxx system variables and the INFORMATION_SCHEMA.OPTIMIZER_TRACE table, but is subject to change.
https://dev.mysql.com/doc/internals/en/optimizer.html
This chapter describes the operation of the MySQL Query optimizer, which is used to determine the most efficient means for executing queries.
https://dev.mysql.com/doc/internals/en/providing-index-information-to-optimizer.html
In order for indexing to be used effectively, storage engines need to provide the optimizer with information about the table and its indexes. This information is used to choose whether to use an index, and if so, which index to use.
https://dev.mysql.com/doc/refman/8.4/en/group-by-optimization.html
If the WHERE clause contains range predicates (see the discussion of the range join type in Section 10.8.1, “Optimizing Queries with EXPLAIN”), a Loose Index Scan looks up the first key of each group that satisfies the range conditions, and ...