Retrieving InnoDB Tablespace Metadata from INFORMATION_SCHEMA.FILES mysql>  CREATE TEMPORARY TABLE t1 (c1 INT PRIMARY KEY) ENGINE=INNODB; mysql>  SELECT * FROM INFORMATION_SCHEMA.INNODB_TEMP_TABLE_INFO\G *************************** 1. row *************************** TABLE_ID: 194 NAME: #sql7a79_1_0 N_COLS: 4 SPACE: 182 2. Query  INNODB_TEMP_TABLE_INFO  to view the temporary table metadata. 3. Restart MySQL and query  INNODB_TEMP_TABLE_INFO . The  TABLE_ID   is a unique identifier for the temporary table. The  NAME  column displays the system- generated name for the temporary table, which is prefixed with “#sql” . The number of columns ( N_COLS ) is 4 rather than 1 because  InnoDB  always creates three hidden table columns ( DB_ROW_ID , DB_TRX_ID , and  DB_ROLL_PTR ). An empty set is returned because  INNODB_TEMP_TABLE_INFO  and its data are not persisted to disk when the server is shut down. mysql>  SELECT * FROM INFORMATION_SCHEMA.INNODB_TEMP_TABLE_INFO\G mysql>  CREATE TEMPORARY TABLE t1 (c1 INT PRIMARY KEY) ENGINE=INNODB; 4. Create a new temporary table. 5. Query  INNODB_TEMP_TABLE_INFO  to view the temporary table metadata. mysql>  SELECT * FROM INFORMATION_SCHEMA.INNODB_TEMP_TABLE_INFO\G *************************** 1. row *************************** TABLE_ID: 196 NAME: #sql7b0e_1_0 N_COLS: 4 SPACE: 184 The  SPACE  ID may be different because it is dynamically generated when the server is started. 15.15.8 Retrieving InnoDB Tablespace Metadata from INFORMATION_SCHEMA.FILES The  INFORMATION_SCHEMA.FILES  table provides metadata about all  InnoDB  tablespace types including file-per-table tablespaces, general tablespaces, the system tablespace, temporary table tablespaces, and undo tablespaces (if present). This section provides  InnoDB -specific usage examples. For more information about data provided by the  INFORMATION_SCHEMA.FILES  table, see Section 26.3.15, “The INFORMATION_SCHEMA FILES Table” . The  INNODB_TABLESPACES  and  INNODB_DATAFILES  tables also provide metadata about  InnoDB  tablespaces, but data is limited to file-per-table, general, and undo tablespaces. This query retrieves metadata about the  InnoDB  system tablespace from fields of the  INFORMATION_SCHEMA.FILES  table that are pertinent to  InnoDB  tablespaces. INFORMATION_SCHEMA.FILES  fields that are not relevant to  InnoDB  always return NULL, and are excluded from the query. Note 3330