InnoDB is a transaction-safe storage engine for MySQL that has commit, rollback, and crash-recovery capabilities to protect user data. It stores user data in clustered indexes to reduce I/O for common queries based on primary keys. To maintain data integrity, InnoDB also supports FOREIGN KEY referential-integrity constraints.InnoDB has been designed for maximum performance when processing large data volumes. Its CPU efficiency is probably not matched by any other disk-based relational database engine.The InnoDB storage engine maintains its own buffer pool for caching data and indexes in main memory. InnoDB stores its tables and indexes in a tablespace, which may consist of several files .
InnoDB is used in production at numerous large database sites requiring high performance.