Database-Management-System

Question 29

For the schedule given below, which of the following is Correct?
1 Read A
2 Read B
3 Write A

4 Read A
5 Write A
6 Write B
7 Read B
8 Write B

A	This schedule is serialized and can occur in a scheme using 2PL protocol
B	This schedule is serializable but cannot occur in a scheme using 2PL protocol
C	This schedule is not serialiable but can occur in a scheme using 2PL protocol
D	This schedule is not seralisable and cannot occur in a scheme using 2PL protocol.

Question 29 Explanation:

Let’s draw precedence graph,

Since cycle exist so not conflict serializable.
And we know that if the schedule is not serializable then it is not 2PL.
Hence correct option is (D).

Correct Answer: D

Question 29 Explanation:

Let’s draw precedence graph,

Since cycle exist so not conflict serializable.
And we know that if the schedule is not serializable then it is not 2PL.
Hence correct option is (D).