This is the Reference Manual for the MySQL Database System, version 5.1, through release 5.1.28. It is not intended for use with older versions of the MySQL software due to the many functional and other differences between MySQL 5.1 and previous versions. If you are using an earlier release of the MySQL software, please refer to the MySQL 5.0 Reference Manual, which covers the 5.0 series of MySQL software releases, or to MySQL 3.23, 4.0, 4.1 Reference Manual, which covers the 3.23, 4.0, and 4.1 series of MySQL software releases. Differences between minor versions of MySQL 5.1 are noted in the present text with reference to release numbers (5.1.x).