5.4.7. InnoDB File-Format Management

As InnoDB evolves, new on-disk data structures are sometimes required to support new features. Features such as compressed tables (see Section 5.4.6, "Working with InnoDB Compressed Tables"), and long variable-length columns stored off-page (see Section 5.4.8, "How InnoDB Stores Variable-Length Columns") require data file formats that are not compatible with prior versions of InnoDB. These features both 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, downgrading the file format, and file format names that may be used in the future.

Named File Formats. InnoDB 1.1 has the idea of a named file format and a configuration parameter to enable the use of features that require use of that format. The new file format is the Barracuda format, and the original InnoDB file format is called Antelope. Compressed tables and the new row format that stores long columns "off-page" require the use of the Barracuda file format or newer. Future versions of InnoDB may introduce a series of file formats, identified with the names of animals, in ascending alphabetic order.