W3cubDocs

/MariaDB

Information Schema INDEX_STATISTICS Table

MariaDB 5.2.0

The INDEX_STATISTICS table was introduced in MariaDB 5.2.0 as part of the User Statistics feature.

The Information Schema INDEX_STATISTICS table shows statistics on index usage and makes it possible to do such things as locating unused indexes and generating the commands to remove them.

This is part of the User Statistics feature, which is not enabled by default.

It contains the following columns:

Field	Type	Notes
`TABLE_SCHEMA`	`VARCHAR(192)`	The schema (database) name.
`TABLE_NAME`	`VARCHAR(192)`	The table name.
`INDEX_NAME`	`VARCHAR(192)`	The index name (as visible in `SHOW CREATE TABLE`).
`ROWS_READ`	`INT(21)`	The number of rows read from this index.

Example

SELECT * FROM information_schema.INDEX_STATISTICS 
WHERE TABLE_NAME = "author";
+--------------+------------+------------+-----------+
| TABLE_SCHEMA | TABLE_NAME | INDEX_NAME | ROWS_READ |
+--------------+------------+------------+-----------+
| books        | author     | by_name    |        15 |
+--------------+------------+------------+-----------+

Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.

© 2019 MariaDB
Licensed under the Creative Commons Attribution 3.0 Unported License and the GNU Free Documentation License.
https://mariadb.com/kb/en/information-schema-index_statistics-table/