The INFORMATION_SCHEMA STATISTICS Table The following statements are  not  equivalent: SELECT ... FROM INFORMATION_SCHEMA.SCHEMA_PRIVILEGES SHOW GRANTS ... 26.3.34 The INFORMATION_SCHEMA STATISTICS Table The  STATISTICS  table provides information about table indexes. Columns in  STATISTICS  that represent table statistics hold cached values. The information_schema_stats_expiry  system variable defines the period of time before cached table statistics expire. The default is 86400 seconds (24 hours). If there are no cached statistics or statistics have expired, statistics are retrieved from storage engines when querying table statistics columns. To update cached values at any time for a given table, use  ANALYZE TABLE . To always retrieve the latest statistics directly from storage engines, set  information_schema_stats_expiry=0 . For more information, see Section 8.2.3, “Optimizing INFORMATION_SCHEMA Queries” . If the  innodb_read_only  system variable is enabled,  ANALYZE TABLE may fail because it cannot update statistics tables in the data dictionary, which use  InnoDB . For  ANALYZE TABLE  operations that update the key distribution, failure may occur even if the operation updates the table itself (for example, if it is a  MyISAM  table). To obtain the updated distribution statistics, set information_schema_stats_expiry=0 . The  STATISTICS  table has these columns: Note The name of the catalog to which the table containing the index belongs. This value is always  def . The name of the schema (database) to which the table containing the index belongs. The name of the table containing the index. 0 if the index cannot contain duplicates, 1 if it can. The name of the schema (database) to which the index belongs. The name of the index. If the index is the primary key, the name is always  PRIMARY . The column sequence number in the index, starting with 1. • TABLE_CATALOG • TABLE_SCHEMA • TABLE_NAME • NON_UNIQUE • INDEX_SCHEMA • INDEX_NAME • SEQ_IN_INDEX • COLUMN_NAME 4821