information-schema-statistics.md

title	summary
STATISTICS	Learn the `STATISTICS` information_schema table.

STATISTICS

The STATISTICS table provides information about table indexes.

{{< copyable "sql" >}}

USE information_schema;
DESC statistics;

+---------------+---------------+------+------+---------+-------+
| Field         | Type          | Null | Key  | Default | Extra |
+---------------+---------------+------+------+---------+-------+
| TABLE_CATALOG | varchar(512)  | YES  |      | NULL    |       |
| TABLE_SCHEMA  | varchar(64)   | YES  |      | NULL    |       |
| TABLE_NAME    | varchar(64)   | YES  |      | NULL    |       |
| NON_UNIQUE    | varchar(1)    | YES  |      | NULL    |       |
| INDEX_SCHEMA  | varchar(64)   | YES  |      | NULL    |       |
| INDEX_NAME    | varchar(64)   | YES  |      | NULL    |       |
| SEQ_IN_INDEX  | bigint(2)     | YES  |      | NULL    |       |
| COLUMN_NAME   | varchar(21)   | YES  |      | NULL    |       |
| COLLATION     | varchar(1)    | YES  |      | NULL    |       |
| CARDINALITY   | bigint(21)    | YES  |      | NULL    |       |
| SUB_PART      | bigint(3)     | YES  |      | NULL    |       |
| PACKED        | varchar(10)   | YES  |      | NULL    |       |
| NULLABLE      | varchar(3)    | YES  |      | NULL    |       |
| INDEX_TYPE    | varchar(16)   | YES  |      | NULL    |       |
| COMMENT       | varchar(16)   | YES  |      | NULL    |       |
| INDEX_COMMENT | varchar(1024) | YES  |      | NULL    |       |
| IS_VISIBLE    | varchar(3)    | YES  |      | NULL    |       |
| Expression    | varchar(64)   | YES  |      | NULL    |       |
+---------------+---------------+------+------+---------+-------+
18 rows in set (0.00 sec)

The following statements are equivalent:

SELECT * FROM INFORMATION_SCHEMA.STATISTICS
  WHERE table_name = 'tbl_name'
  AND table_schema = 'db_name'

SHOW INDEX
  FROM tbl_name
  FROM db_name