engineering recuitment NIC NIELIT Scientist B 2023 Mock Test DBMS Concurrency Control Two Phase Locking Protocol
Consider the following two-phase locking protocol. Suppose a transaction T accesses (for read or write operations), a certain set of objects {O1,…,Ok}. This is done in the following manner:
Step 1. T acquires exclusive locks to O1,…,Ok in increasing order of their addresses.
Step 2. The required operations are performed.
Step 3. All locks are released.
This protocol will1
guarantee serializability and deadlock-freedom
2
guarantee neither serializability nor deadlock-freedom
3
guarantee serializability but not deadlock-freedom
4
guarantee deadlock-freedom but not serializability