Question 152 – ISRO-2018
June 1, 2024Question 159 – ISRO-2018
June 2, 2024Transactions
| Question 67 |
Let us assume that transaction T1 has arrived before transaction T2. Consider the schedule
S=r1(A); r2(B) ; w2(A); w1(B)
Which of the following is true?
S=r1(A); r2(B) ; w2(A); w1(B)
Which of the following is true?
| Allowed under basic timestamp protocol. | |
| Not allowed under basic timestamp protocols because T1 is rolled back | |
| Not allowed under basic timestamp protocols because T2 is rolled back | |
| None of these |
Question 67 Explanation:
→ There are 2 conflicting actions a and b is shown in above diagram.
→ In timestamp ordering protocol, conflicting actions in ascending order time-stamps are allowed i.e ‘a’ is allowed but not ‘b’.
→ So we need to roll back T1 after that only it will be allowed. Because of all conflicting actions in ascending order timestamps in below diagram.
Correct Answer: B
Question 67 Explanation:
→ There are 2 conflicting actions a and b is shown in above diagram.
→ In timestamp ordering protocol, conflicting actions in ascending order time-stamps are allowed i.e ‘a’ is allowed but not ‘b’.
→ So we need to roll back T1 after that only it will be allowed. Because of all conflicting actions in ascending order timestamps in below diagram.
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