This is the Reference Manual for the MySQL Database System, version 5.5, through release 5.5.9. Differences between minor versions of MySQL 5.5 are noted in the present text with reference to release numbers (5.5.x).

This manual is not intended for use with older versions of the MySQL software due to the many functional and other differences between MySQL 5.5 and previous versions. If you are using an earlier release of the MySQL software, please refer to the appropriate manual. For example, MySQL 5.1 Reference Manual, covers the 5.1 series of MySQL software releases.

If you are using MySQL 5.6, please refer to the MySQL 5.6 Reference Manual.

Because this manual serves as a reference, it does not provide general instruction on SQL or relational database concepts. It also does not teach you how to use your operating system or command-line interpreter.

The MySQL Database Software is under constant development, and the Reference Manual is updated frequently as well. The most recent version of the manual is available online in searchable form at http://dev.mysql.com/doc/. Other formats also are available there, including HTML, PDF, and Windows CHM versions.

The Reference Manual source files are written in DocBook XML format. The HTML version and other formats are produced automatically, primarily using the DocBook XSL stylesheets. For information about DocBook, see http://docbook.org/

If you have questions about using MySQL, you can ask them using our mailing lists or forums. See Section 1.6.1, “MySQL Mailing Lists”, and Section 1.6.2, “MySQL Community Support at the MySQL Forums”. If you have suggestions concerning additions or corrections to the manual itself, please send them to the http://www.mysql.com/company/contact/.

This manual was originally written by David Axmark and Michael “Monty” Widenius. It is maintained by the MySQL Documentation Team, consisting of Paul DuBois, Stefan Hinz, Jon Stephens, Tony Bedford, and John Russell.