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mysql.innodb_index_stats

The mysql.innodb_index_stats table stores data related to particular InnoDB Persistent Statistics, and contains multiple rows for each index.

This table, along with the related mysql.innodb_table_stats table, can be manually updated in order to force or test differing query optimization plans. After updating, FLUSH TABLE innodb_index_stats is required to load the changes.

mysql.innodb_index_stats is not replicated, although any ANALYZE TABLE statements on the table will be by default..

It contains the following fields:

Field	Type	Null	Key	Default	Description
`database_name`	`varchar(64)`	NO	PRI	`NULL`	Database name.
`table_name`	`varchar(64)`	NO	PRI	`NULL`	Table, partition or subpartition name.
`index_name`	`varchar(64)`	NO	PRI	`NULL`	Index name.
`last_update`	`timestamp`	NO		`current_timestamp()`	Time that this row was last updated.
`stat_name`	`varchar(64)`	NO	PRI	`NULL`	Statistic name.
`stat_value`	`bigint(20) unsigned`	NO		`NULL`	Estimated statistic value.
`sample_size`	`bigint(20) unsigned`	YES		`NULL`	Number of pages sampled for the estimated statistic value.
`stat_description`	`varchar(1024)`	NO		`NULL`	Statistic description.

Example

SELECT * FROM mysql.innodb_index_stats\G
*************************** 1. row ***************************
   database_name: mysql
      table_name: gtid_slave_pos
      index_name: PRIMARY
     last_update: 2017-08-19 20:38:34
       stat_name: n_diff_pfx01
      stat_value: 0
     sample_size: 1
stat_description: domain_id
*************************** 2. row ***************************
   database_name: mysql
      table_name: gtid_slave_pos
      index_name: PRIMARY
     last_update: 2017-08-19 20:38:34
       stat_name: n_diff_pfx02
      stat_value: 0
     sample_size: 1
stat_description: domain_id,sub_id
*************************** 3. row ***************************
   database_name: mysql
      table_name: gtid_slave_pos
      index_name: PRIMARY
     last_update: 2017-08-19 20:38:34
       stat_name: n_leaf_pages
      stat_value: 1
     sample_size: NULL
stat_description: Number of leaf pages in the index
*************************** 4. row ***************************
   database_name: mysql
      table_name: gtid_slave_pos
      index_name: PRIMARY
     last_update: 2017-08-19 20:38:34
       stat_name: size
      stat_value: 1
     sample_size: NULL
stat_description: Number of pages in the index
*************************** 5. row ***************************
   database_name: test
      table_name: ft
      index_name: FTS_DOC_ID_INDEX
     last_update: 2017-09-15 12:58:39
       stat_name: n_diff_pfx01
      stat_value: 0
     sample_size: 1
stat_description: FTS_DOC_ID
*************************** 6. row ***************************
   database_name: test
      table_name: ft
      index_name: FTS_DOC_ID_INDEX
     last_update: 2017-09-15 12:58:39
       stat_name: n_leaf_pages
      stat_value: 1
     sample_size: NULL
stat_description: Number of leaf pages in the index
...

mysql.innodb_index_stats

Example

See Also