By default, InnoDB
reads uncommitted data when calculating statistics. In the case of an uncommitted transaction that deletes rows from a table, delete-marked records are excluded when calculating row estimates and index statistics, which can lead to non-optimal execution plans for other transactions that are operating on the table concurrently using a transaction isolation level other than READ UNCOMMITTED
. To avoid this scenario, innodb_stats_include_delete_marked
can be enabled to ensure that delete-marked records are included when calculating persistent optimizer statistics.
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.