MySQL Databases

MySQL is a relational database management system (RDBMS) that has more than 11 million installations. MySQL is named after Monty Widenius's daughter My. The program runs as a server providing multi-user access to a number of databases. MySQL is officially pronounced /maɪˌɛskjuːˈɛl/ (My S-Q-L), but often pronounced /maɪˌsiː'kwɛl/ (My SeQueL).

The project has made its source code available under the terms of the GNU General Public License, as well as under a variety of proprietary agreements. MySQL is owned and sponsored by a single for-profit firm, the Swedish company MySQL AB, now a subsidiary of Sun Microsystems. As of 2009 Oracle Corporation began the process of acquiring Sun Microsystems.

In response to the Oracle acquisition, members of the MySQL community have created several forks such as Drizzle and MariaDB in fear that Oracle would hurt the development of MySQL because it is a competitor to the company's own database products.

MySQL is often used in free software projects that require a full-featured database management system, including projects such as WordPress, phpBB and other software built on the LAMP software stack. It is also used in many high-profile, large-scale World Wide Web products including Wikipedia, Google, Drupal and Facebook.

Features

• A broad subset of ANSI SQL 99, as well as extensions
• Cross-platform support
• Stored procedures
• Triggers
• Cursors
• Updatable Views
• True Varchar support
• INFORMATION_SCHEMA
• Strict mode
• X/Open XA distributed transaction processing (DTP) support; two phase commit as part of this, using Oracle's InnoDB engine
• Independent storage engines (MyISAM for read speed, InnoDB for transactions and referential integrity, MySQL Archive for storing historical data in little space)
• Transactions with the InnoDB, BDB and Cluster storage engines; savepoints with InnoDB
• SSL support
• Query caching
• Sub-SELECTs (i.e. nested SELECTs)
• Replication support (i.e. Master-Master Replication and Master-Slave Replication) with one master per slave, many slaves per master, no automatic support for multiple masters per slave.
• Full-text indexing and searching using MyISAM engine
• Embedded database library
• Partial Unicode support (UTF-8 and UCS-2 encoded strings are limited to the BMP)
• Partial ACID compliance (full compliance only when using the non-default storage engines InnoDB, BDB and Cluster)
• Shared-nothing clustering through MySQL Cluster
• Hot backup (via mysqlhotcopy) under certain conditions

source: Wikipedia