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Where are InnoDB table statistics stored in MySQL?
InnoDB stores statistics in the “mysql” database, in the tables innodb_table_stats and innodb_index_stats. Since they are regular MySQL tables, privileged users can access them.
What’s the maximum row size for an InnoDB table?
The maximum row size for an InnoDB table, which applies to data stored locally within a database page, is slightly less than half a page for 4KB, 8KB, 16KB, and 32KB 11 varchar fields > 255 characters (utf-8 on mysql = 3 bytes per char). Remember, it will only overflow to an overflow page if the field is > 767 bytes.
When to use InnoDB stats include delete marked?
When innodb_stats_include_delete_marked is enabled, ANALYZE TABLE considers delete-marked records when recalculating statistics. innodb_stats_include_delete_marked is a global setting that affects all InnoDB tables, and it is only applicable to persistent optimizer statistics.
How to update InnoDB table statistics manually Percona database?
Instead it looks at random pages, as determined by options innodb_stats_sample_pages, innodb_stats_transient_sample_pages and innodb_stats_persistent_sample_pages, or by the CREATE TABLE option STATS_SAMPLE_PAGES. The default value for persistent statistics is 20.
How does InnoDB calculate the cardinality of an index?
When InnoDB calculates the cardinality of an index, it does not scan the full table by default. Instead it looks at random pages, as determined by options innodb_stats_sample_pages, innodb_stats_transient_sample_pages and innodb_stats_persistent_sample_pages, or by the CREATE TABLE option STATS_SAMPLE_PAGES.
How to check the integrity of all databases?
The first command will check the integrity for all tables of all databases, if there’s any corruption your table will be repaired automatically. And the second will additionally optimize the table on disk. Thanks for contributing an answer to Database Administrators Stack Exchange! Please be sure to answer the question.