As InnoDB evolves, data file formats that are not
compatible with prior versions of InnoDB are
sometimes required to support new features. To help manage
compatibility in upgrade and downgrade situations, and systems that
run different versions of MySQL, InnoDB uses
named file formats. InnoDB currently supports two
named file formats, Antelope
and Barracuda.
Antelope is the original
InnoDB file format, which previously did not
have a name. It supports
COMPACT and
REDUNDANT row
formats for InnoDB tables and is the default
file format in MySQL 5.6 to ensure maximum compatibility with
earlier MySQL versions that do not support the Barracuda file
format.
Barracuda is the newest
file format. It supports all InnoDB row
formats including the newer
COMPRESSED and
DYNAMIC row
formats. The features associated with
COMPRESSED and
DYNAMIC row
formats include compressed tables, efficient storage of off-page
columns, and index key prefixes up to 3072 bytes
(innodb_large_prefix). See
Section 14.11, “InnoDB Row Storage and Row Formats”.
This section discusses enabling InnoDB file
formats, verifying compatibility of different file formats between
MySQL releases, identifying the file format in use, and downgrading
the file format.