Percona XtraDB

• Percona

• Comparison of MySQL database engines
• SHOW INNODB STATUS walkthrough

Percona XtraDB is an enhanced version of InnoDB database engine.

InnoDB features:

• Default storage engine in MySQL 5.5
• InnoDB recovers from a crash or other unexpected shutdown by replaying its logs
• InnoDB automatically groups together multiple concurrent inserts and flushes them to disk at the same time
• ACID compliant
• Transactional support: data integrity is guaranteed in the entire query process
• InnoDB uses row-level locking, as opposed to table locking in MyISAM. InnoDB can modify multiple rows concurrently, where MyISAM can only do one at a time
• Full text search (same as MyISAM)
• Foreign key constraints
• Designed for high performance
• Hot backup: do a full backup while reads/writes are still happening
• Updates are written to the log first, and then the changes are made to the database

XtraDB features:

• Backwards compatible with InnoDB
• Faster performance
• Better scalability
• Better tunability
• More statistics
• Improvements in handing multiple concurrent queries
• NoSQL support (experimental): You can access your data with both NoSQL and SQL statements
• Increased shutdown times
• Corrupted tables are disabled, instead of bringing down the database server
• Can export single tables (n/a in InnoDB)
• Buffer is saved during restarts
• Slow query logs in microseconds instead of in seconds
• Improved SHOW INNODB STATUS
• Improved SHOW PROCESSLIST