Although two-phase locking guarantees serializability, another problem called a deadlock can occur. A deadlock occurs during two-phase locking when a transaction is waiting for an item that is locked exclusively by another.
What is two phases locking will two phase locking result in deadlock?
Deadlocks in 2PL
Locks block data-access operations. Mutual blocking between transactions results in a deadlock, where execution of these transactions is stalled, and no completion can be reached. Thus deadlocks need to be resolved to complete these transactions' executions and release related computing resources.
Is deadlock possible in 2 phase locking protocol justify your answer with an example?
Deadlock in 2-PL –
Say we have two transactions T1 and T2. Drawing the precedence graph, you may detect the loop. So Deadlock is also possible in 2-PL. Two-phase locking may also limit the amount of concurrency that occurs in a schedule because a Transaction may not be able to release an item after it has used it.
