InnoDB

InnoDB is a storage engine for MySQL. MySQL 5.5 and later use it by default. It provides the standard ACID-compliant transaction features, along with foreign key support (Declarative Referential Integrity). It is included as standard in most binaries distributed by MySQL AB, the exception being some OEM versions.

InnoDB became a product of Oracle Corporation after its acquisition of Innobase Oy in October 2005.^[1] The software is dual licensed; it is distributed under the GNU General Public License, but can also be licensed to parties wishing to combine InnoDB in proprietary software.^[2]

MariaDB and Percona Server use a fork of InnoDB called XtraDB by default. XtraDB is maintained by Percona. Oracle InnoDB's changes are regularly imported into XtraDB, and some bug fixes and extra features are added.

InnoDB supports:

• Both SQL and XA transactions
• Tablespaces
• Foreign keys
• FULLTEXT indexes, since MySQL 5.6 and MariaDB 10.0
• Spatial operations, following the OpenGIS standard
• Virtual columns, only in MariaDB^{[citation needed]}

• Comparison of MySQL database engines

• Mysqltutorial.org, InnoDB and other table types in MySQL
• Not-so-well-known differences between MyISAM and InnoDB MySQL server storage engines
• The InnoDB Storage Engine, in the MySQL manual.