14.11 InnoDB File-Format Management

14.11.1 Enabling File Formats
14.11.2 Verifying File Format Compatibility
14.11.3 Identifying the File Format in Use
14.11.4 Downgrading the File Format

As InnoDB evolves, new on-disk data structures are sometimes required to support new features. Features such as compressed tables (see Section 14.10, “InnoDB Compressed Tables”), long variable-length columns stored off-page (see Section 14.12, “InnoDB Row Storage and Row Formats”), and index key prefixes up to 3072 bytes (innodb_large_prefix) require data file formats that are not compatible with prior versions of InnoDB. These features require use of the new Barracuda file format.

This section discusses enabling file formats for new InnoDB tables, verifying compatibility of different file formats between MySQL releases, identifying the file format in use, and downgrading the file format.

Named File Formats.  InnoDB 1.1 uses named file formats to help manage compatibility in upgrade and downgrade situations, or heterogeneous systems running different levels of MySQL. Currently, Antelope and Barracuda file formats are supported. Barracuda is the newest file format. It supports important InnoDB features such as compressed tables and the DYNAMIC row format for more efficient BLOB storage. The original InnoDB file format, which previously did not have a name, is now known as Antelope.