Percona XtraDB Storage Engine for MySQL
Percona XtraDB is an enhanced version of the InnoDB storage engine for MySQL® and MariaDB®. It has much faster performance than InnoDB and better scalability on modern hardware. XtraDB has more features than InnoDB; these are useful in high-load environments. It is backwards-compatible with InnoDB, so you can use it as a drop-in replacement.
Percona XtraDB includes all of InnoDB's reliable ACID-compliant design and advanced MVCC architecture. It adds features, tunability, metrics, and scalability. In particular, it is designed to scale better than InnoDB on many cores, to use memory more efficiently than InnoDB, and to be more convenient and usable than InnoDB. The new features are specially designed to overcome some of InnoDB's limitations. We choose enhancements based on customer requests, and on our best judgment of real-world needs as a high-performance consulting company.