This is the most restrictive lock mode which conflicts with all other lock modes and protects a locked table from any concurrent operations. The lock was successfully applied. Message returned if name does not exist. Postgres always uses the least restrictive lock mode whenever possible. ROW Locks individual rows.
Locks exist for the duration of the transaction.
Instead, it should update rows R1 and R2 in the same order as the first application. If multiple lock modes are involved, then transactions should always acquire the most restrictive mode first. Notes LOCK is a Postgres language extension. LOCK works only inside transactions.