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 ...

See Also

• InnoDB Persistent Statistics

• mysql.innodb_table_stats

• ANALYZE TABLE

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