17.7 InnoDB Locking and Transaction Model (original) (raw)

To implement a large-scale, busy, or highly reliable database application, to port substantial code from a different database system, or to tune MySQL performance, it is important to understandInnoDB locking and the InnoDB transaction model.

This section discusses several topics related toInnoDB locking and the InnoDB transaction model with which you should be familiar.

• Section 17.7.1, “InnoDB Locking” describes lock types used byInnoDB.
• Section 17.7.2, “InnoDB Transaction Model” describes transaction isolation levels and the locking strategies used by each. It also discusses the use ofautocommit, consistent non-locking reads, and locking reads.
• Section 17.7.3, “Locks Set by Different SQL Statements in InnoDB” discusses specific types of locks set in InnoDB for various statements.
• Section 17.7.4, “Phantom Rows” describes howInnoDB uses next-key locking to avoid phantom rows.
• Section 17.7.5, “Deadlocks in InnoDB” provides a deadlock example, discusses deadlock detection, and provides tips for minimizing and handling deadlocks in InnoDB.