14.5.5.2 deadlock detection and Rollback deadlock detection and rollback

14.5.5.2 deadlock detection and Rollback  deadlock detection and rollback

InnoDB automatic transaction deadlock and rollback a transaction

InnoDB try to pick a small transaction to roll back and forth, the size of the transaction is Rows inserted, updated, or deleted the number of determined


InnoDB know the table lock if Innodb_table_locks = 1 (the default) and autocommit = 0, 


MySQL level knows about row locks

Otherwise, InnoDB cannot detect deadlocks a table table is set through a lock tables statement or set through a storage engine.


solve those problems by setting the value of the Innodb_lock_wait_timeout system variable


when InnoDB performs a full transaction rollback, all locks set by the transaction are freed.


However, if just a separate SQL statement is rolled back as an error result,


Some locks set by the statement may be saved.