Because InnoDB 1.1 supports the “Barracuda” file format, with new on-disk data structures within both the database and log files, pay special attention to file format compatibility with respect to the following scenarios:
Downgrading from MySQL 5.5 to the MySQL 5.1 or earlier (without the InnoDB Plugin enabled), or otherwise using earlier versions of MySQL with database files created by MySQL 5.5 and higher.
Using MySQL replication.
Using MySQL Enterprise Backup or InnoDB Hot Backup.
WARNING: Once you create any
tables with the Barracuda file format, take care to avoid crashes
and corruptions when using those files with an earlier version of
MySQL. It is strongly
recommended that you use a “slow shutdown”
SET GLOBAL innodb_fast_shutdown=0) when
stopping the MySQL server before downgrading to MySQL 5.1 or
earlier. This ensures that the log files and other system
information do not cause consistency issues or startup problems
when using a prior version of MySQL.
WARNING: If you dump a database
containing compressed tables with
the dump file may contain
TABLE statements that attempt to create compressed
tables, or those using
the new database. Therefore, be sure the new database is running
the InnoDB storage engine, with the proper settings for
innodb_file_per_table, if you
want to have the tables re-created as they exist in the original
database. Typically, when the
mysqldump file is
loaded, MySQL and InnoDB ignore
TABLE options they do not recognize, and the table(s)
are created in a format used by the running server.
WARNING: If you use MySQL
replication, ensure all slaves are configured with the
InnoDB storage engine, with the same settings for
innodb_file_per_table. If you do
not do so, and you create tables that require the new Barracuda
file format, replication errors may occur. If a slave MySQL server
is running an older version of MySQL, it ignores the
CREATE TABLE options to create a
compressed table or one with
ROW_FORMAT=DYNAMIC, and creates the table
WARNING: Version 3.0 of
InnoDB Hot Backup does not support the new Barracuda file format. Using
InnoDB Hot Backup Version 3 to backup databases in this format causes
unpredictable behavior. MySQL Enterprise Backup, the successor product to
InnoDB Hot Backup, does support tables with the Barracuda file format.
You can also back up such databases with