# Does the following modified Two-Phase Locking protocol ensure serializability and freedom from deadlock?

Consider the following variant of the two phase locking protocol. Suppose a transaction $T$ accesses (for read or write operations), a certain set of objects ${O_1,...,O_k}$.

The modified algorithm works as :

Step 1. $T$ acquires exclusive locks to $O_1, . . . , O_k$ in increasing order of their ids.

Step 2. The required operations are performed.

Step 3. All locks are released.

Does this protocol ensure serializability and freedom from deadlock?

Since the locks are being obtained in an increasing order of their ids, the circular wait condition cannot prevail and a deadlock can thus be avoided. But does it ensure serializability? How to argue with respect to the serialization aspect?