The mysql.index_stats table was introduced as part of the Engine-independent table statistics feature implemented in MariaDB 10.0.1.
The mysql.index_stats table is one of three tables storing data used for Engine-independent table statistics added in MariaDB 10.0.1. The others are mysql.column_stats and mysql.table_stats.
In MariaDB 10.4 and later, this table uses the Aria storage engine.
In MariaDB 10.3 and before, this table uses the MyISAM storage engine.
The mysql.index_stats table contains the following fields:
| Field | Type | Null | Key | Default | Description |
|---|---|---|---|---|---|
db_name |
varchar(64) |
NO | PRI | NULL |
Database the table is in. |
table_name |
varchar(64) |
NO | PRI | NULL |
Table name |
index_name |
varchar(64) |
NO | PRI | NULL |
Name of the index |
prefix_arity |
int(11) unsigned |
NO | PRI | NULL |
Index prefix length. 1 for the first keypart, 2 for the first two, and so on. InnoDB's extended keys are supported. |
avg_frequency |
decimal(12,4) |
YES | NULL |
Average number of records one will find for given values of (keypart1, keypart2, ..), provided the values will be found in the table. |
It is possible to manually update the table. See Manual updates to statistics tables for details.
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Licensed under the Creative Commons Attribution 3.0 Unported License and the GNU Free Documentation License.
https://mariadb.com/kb/en/mysqlindex_stats-table/