14.7 InnoDB Locking and Transaction Model

14.7.1 InnoDB Locking

14.7.2 InnoDB Transaction Model

14.7.3 Locks Set by Different SQL Statements in InnoDB

14.7.4 Phantom Rows

14.7.5 Deadlocks in InnoDB

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 understand InnoDB locking and the InnoDB transaction model.

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

• Section 14.7.1, “InnoDB Locking” describes lock types used by InnoDB.

• Section 14.7.2, “InnoDB Transaction Model” describes transaction isolation levels and the locking strategies used by each. It also discusses the use of autocommit, consistent non-locking reads, and locking reads.

• Section 14.7.3, “Locks Set by Different SQL Statements in InnoDB” discusses specific types of locks set in InnoDB for various statements.

• Section 14.7.4, “Phantom Rows” describes how InnoDB uses next-key locking to avoid phantom rows.

• Section 14.7.5, “Deadlocks in InnoDB” provides a deadlock example, discusses deadlock detection, and provides tips for minimizing and handling deadlocks in InnoDB.