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https://dev.mysql.com/doc/refman/8.0/en/innodb-persistent-stats.html
Note For nonunique indexes, InnoDB appends the columns of the primary key. The persistent optimizer statistics feature improves plan stability by storing statistics to disk and making them persistent across server restarts so that the optimizer is ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-preload-buffer-pool.html
For example: mysql> SELECT EVENT_NAME, WORK_COMPLETED, WORK_ESTIMATED FROM performance_schema.events_stages_history; +-------------------------------+----------------+----------------+ | EVENT_NAME | WORK_COMPLETED | WORK_ESTIMATED | ... To reduce ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-read-only-instance.html
Note This feature is mainly intended for flexibility in distribution and deployment, rather than raw performance based on the read-only aspect. You can query InnoDB tables where the MySQL data directory is on read-only media by enabling the ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-statistics-estimation.html
SET GLOBAL innodb_stats_on_metadata=ON Note innodb_stats_on_metadata only applies when optimizer statistics are configured to be non-persistent (when innodb_stats_persistent is disabled). Optimizer statistics are not persisted to disk when ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-transaction-isolation-levels.html
Transaction isolation is one of the foundations of database processing. Isolation is the I in the acronym ACID; the isolation level is the setting that fine-tunes the balance between performance and reliability, consistency, and reproducibility of ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-transaction-scheduling.html
Note Prior to MySQL 8.0.20, InnoDB also uses a First In First Out (FIFO) algorithm to schedule transactions, and the CATS algorithm is used under heavy lock contention only. InnoDB uses the Contention-Aware Transaction Scheduling (CATS) algorithm ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-undo-logs.html
Note It is possible to encounter a concurrent transaction limit error before reaching the number of concurrent read-write transactions that InnoDB is capable of supporting. An undo log is a collection of undo log records associated with a single ...
https://dev.mysql.com/doc/refman/8.0/en/insert-on-duplicate.html
If you specify an ON DUPLICATE KEY UPDATE clause and a row to be inserted would cause a duplicate value in a UNIQUE index or PRIMARY KEY, an UPDATE of the old row occurs. If column b is also unique, the INSERT is equivalent to this UPDATE statement ...
https://dev.mysql.com/doc/refman/8.0/en/insert-select.html
INSERT [LOW_PRIORITY | HIGH_PRIORITY] [IGNORE] [INTO] tbl_name [PARTITION (partition_name [, partition_name] ...)] [(col_name [, col_name] ...)] { SELECT ... | TABLE table_name | VALUES row_constructor_list } [ON DUPLICATE KEY UPDATE ...
https://dev.mysql.com/doc/refman/8.0/en/installation-layouts.html
Note that the layout of installations from vendors other than Oracle may differ from these layouts. The installation layout differs for different installation types (for example, native packages, binary tarballs, and source tarballs), which can ...