Enum LockWait
What a locking read (ForUpdate / ForShare) does when a row it wants is
already locked by another transaction.
public enum LockWait
Fields
NoWait = 1Fail immediately with a lock error instead of waiting.
SkipLocked = 2Leave locked rows out of the result. The usual choice for job queues.
Wait = 0Block until the other transaction releases the row (or the lock wait times out).