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https://dev.mysql.com/doc/refman/8.0/en/information-schema-optimizer-trace-table.html
The OPTIMIZER_TRACE table provides information produced by the optimizer tracing capability for traced statements. The OPTIMIZER_TRACE table has these columns: QUERY The text of the traced statement. MISSING_BYTES_BEYOND_MAX_MEM_SIZE Each ...
https://dev.mysql.com/doc/refman/8.0/en/information-schema-profiling-table.html
For example, the following queries are equivalent: SHOW PROFILE FOR QUERY 2; SELECT STATE, FORMAT(DURATION, 6) AS DURATION FROM INFORMATION_SCHEMA.PROFILING WHERE QUERY_ID = 2 ORDER BY SEQ; . Its contents correspond to the information produced by ...
https://dev.mysql.com/doc/refman/8.0/en/information-schema-views-table.html
For example, you might use the ANSI SQL mode to ensure MySQL correctly interprets the standard SQL concatenation operator, the double bar (||), in your queries. You must have the SHOW VIEW privilege to access this table. The VIEWS table has these ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-adaptive-hash.html
If a table fits almost entirely in main memory, a hash index speeds up queries by enabling direct lookup of any element, turning the index value into a sort of pointer. If InnoDB notices that queries could benefit from building a hash index, it does ... The adaptive hash index enables InnoDB to perform more like an in-memory database on systems with appropriate combinations of workload and sufficient memory for the buffer pool without sacrificing transactional features or ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-and-mysql-replication.html
It is possible to use replication in a way where the storage engine on the replica is not the same as the storage engine on the source. For example, you can replicate modifications to an InnoDB table on the source to a MyISAM table on the replica.
https://dev.mysql.com/doc/refman/8.0/en/innodb-buffer-pool.html
By default, pages read by queries are immediately moved into the new sublist, meaning they stay in the buffer pool longer. The buffer pool is an area in main memory where InnoDB caches table and index data as it is accessed. The buffer pool permits ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-information-schema-temp-table-info.html
INNODB_TEMP_TABLE_INFO provides information about user-created InnoDB temporary tables that are active in the InnoDB instance. It does not provide information about internal InnoDB temporary tables used by the optimizer. mysql> SHOW TABLES FROM ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-locks-set.html
It is important to create good indexes so that your queries do not scan more rows than necessary. A locking read, an UPDATE, or a DELETE generally set record locks on every index record that is scanned in the processing of an SQL statement. It does ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-memcached-developing.html
You can perform the conversion on the application side, or by using the CAST() function in queries. You might adapt parts of your application that perform single-row queries, inserts, updates, or deletes, to improve performance in critical sections ... Typically, writing an application for the InnoDB memcached plugin involves some degree of rewriting or adapting existing code that uses MySQL or the memcached ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-memcached-tuning.html
Because using InnoDB in combination with memcached involves writing all data to disk, whether immediately or sometime later, raw performance is expected to be somewhat slower than using memcached by itself. Benchmarks suggest that queries and DML ...When using the InnoDB memcached plugin, focus tuning goals for memcached operations on achieving better performance than equivalent SQL ...