statistics

statistics provides information about table indexes.

The following fields are provided in statistics:

Field	Description
TABLE_CATALOG	The name of the catalog to which the table containing the index belongs. This value is always def.
TABLE_SCHEMA	The name of the database to which the table containing the index belongs.
TABLE_NAME	The name of the table containing the index.
NON_UNIQUE	0 if the index cannot contain duplicates, 1 if it can.
INDEX_SCHEMA	The name of the database to which the index belongs.
INDEX_NAME	The name of the index. If the index is the primary key, the name is always PRIMARY.
SEQ_IN_INDEX	The column sequence number in the index, starting with 1.
COLUMN_NAME	The column name. See also the description for the EXPRESSION column.
COLLATION	How the column is sorted in the index. This can have values A (ascending), D (descending), or NULL (not sorted).
CARDINALITY	An estimate of the number of unique values in the index.
SUB_PART	The index prefix. That is, the number of indexed characters if the column is only partly indexed, NULL if the entire column is indexed.
PACKED	Indicates how the key is packed. NULL if it is not.
NULLABLE	Contains YES if the column may contain NULL values and '' if not.
INDEX_TYPE	The index method used (BTREE, FULLTEXT, HASH, RTREE).
COMMENT	Information about the index not described in its own column, such as disabled if the index is disabled.
INDEX_COMMENT	Any comment provided for the index with a COMMENT attribute when the index was created.