# Information Schema INDEX\_STATISTICS Table

The [Information Schema](https://mariadb.com/docs/server/reference/system-tables/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](https://mariadb.com/docs/server/ha-and-performance/optimization-and-tuning/query-optimizations/statistics-for-optimizing-queries/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](https://mariadb.com/docs/server/reference/sql-statements/administrative-sql-statements/show/show-create-table)).                                                              |
| ROWS\_READ    | BIGINT(21)   | The number of rows read from this index.                                                                                                                                                                                        |
| QUERIES       | BIGINT(21)   | Incremented for each index the query is part of. This assists one to see how effective the index is. From [MariaDB 11.5](https://app.gitbook.com/s/aEnK0ZXmUbJzqQrTjFyb/community-server/old-releases/11.5/what-is-mariadb-115) |

## Example

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

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