pessimistic
A methodology that sacrifices performance or concurrency in favor of safety. It is appropriate if a high proportion of requests or attempts might fail, or if the consequences of a failed request are severe. InnoDB uses what is known as a pessimistic locking strategy, to minimize the chance of deadlocks. At the application level, you might avoid deadlocks by using a pessimistic strategy of acquiring all locks needed by a transaction at the very beginning.
Many built-in database mechanisms use the opposite optimistic methodology.
See also deadlock.
See also locking.
See also optimistic.