Skip to content
Related Articles

Related Articles

Improve Article

GATE | GATE-CS-2003 | Question 90

  • Last Updated : 15 Oct, 2019

Consider three data items D1, D2 and D3 and the following execution schedule of transactions T1, T2 and T3. In the diagram, R(D) and W(D) denote the actions reading and writing the data item D respectively.
GATECS2003Q87


Which of the following statements is correct?
(A) The schedule is serializable as T2; T3; T1
(B) The schedule is serializable as T2; T1; T3
(C) The schedule is serializable as T3; T2; T1
(D) The schedule is not serializable


Answer: (D)

Explanation:
T1 and T2 have conflicting operations between them forming a cycle in the precedence graph.

R(D2) of T2, and W(D2) of T1 ( Read-Write Conflict)
R(D1) of T1, and W(D1) of T2 ( Read-Write Conflict)

Hence in the precedence graph of the schedule there would be a cycle between T1 and T2 vertices. Therefore not a serializable schedule.


Quiz of this Question

Attention reader! Don’t stop learning now.  Practice GATE exam well before the actual exam with the subject-wise and overall quizzes available in GATE Test Series Course.

Learn all GATE CS concepts with Free Live Classes on our youtube channel.

My Personal Notes arrow_drop_up
Recommended Articles
Page :