Q5Database Management System
Question
10 marks
Explain the concept of Concurrency Control. Describe the Two-Phase Locking (2PL) protocol in detail.
Answer
2PL ensures serializability via growing and shrinking phases.
The Two-Phase Locking (2PL) protocol requires that each transaction issue lock and unlock requests in two phases: (1) Growing Phase (acquiring locks), (2) Shrinking Phase (releasing locks). Once a lock is released, no more locks can be acquired.