Timestamp Ordering Protocol
Timestamp Ordering Protocol MCQs
Q1
T1 has timestamp TS(T1) = 5, T2 has TS(T2) = 8.
T1 requests W(A), R(A) was last read by T2. Which occurs?
A. T1 proceeds
B. T1 is aborted
C. T2 is aborted
D. Deadlock
✅ Answer: B
Solution:
- Timestamp ordering: TS(T1) < TS(T2), T1 wants to write on A → violates TO rules (write-after-read conflict) → T1 aborted.
Q2
T1: TS = 10, wants to R(B). Last write of B by T2: TS = 12.
What happens?
A. T1 reads successfully
B. T1 is aborted
C. T2 is aborted
D. Both wait
✅ Answer: B
Solution:
- T1 older than last write → read-after-write conflict → T1 aborted (Thomas Write Rule may ignore if allowed, else abort).
Q3
Which of the following ensures conflict-serializable schedules using timestamps?
A. Basic 2PL
B. Strict 2PL
C. Timestamp Ordering (TO)
D. Rigorous 2PL
✅ Answer: C
Solution:
- TO schedules operations based on timestamps → ensures conflict serializability without locks.
Q4
T1: TS=6, requests W(A); last write of A by T2: TS=5.
Can T1 proceed?
A. Yes
B. No, abort T1
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- TS(T1)=6 > last write TS(T2)=5 → no conflict → T1 proceeds.
Q5
T1: TS=4, requests R(A); last write TS(A) = 6.
Which occurs?
A. T1 reads A
B. T1 aborts
C. T2 aborts
D. Deadlock
✅ Answer: B
Solution:
- Read-after-write conflict: T1 older than last write → violates TO rules → T1 aborted.
Q6
T1: TS=7, wants W(B); last read of B by T2: TS=8.
Action?
A. T1 writes successfully
B. T1 aborts
C. T2 aborts
D. Both wait
✅ Answer: B
Solution:
- Write-after-read conflict: T1 older than last read → violates TO → T1 aborted.
Q7
Which property is guaranteed by Timestamp Ordering?
A. Deadlock-free
B. Conflict-serializable
C. Cascading abort-free
D. All of the above
✅ Answer: D
Solution:
- TO protocol: no waits → deadlock-free
- Enforces conflict serializability
- Cascading aborts avoided by aborting conflicting transactions
Q8
T1: TS=10, requests R(A); last write of A TS=8.
Can T1 read?
A. Yes
B. No
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed → T1 reads successfully.
Q9
T1: TS=3, wants W(A); last read by T2: TS=4.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 aborted
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict: T1 older than last read → violates TO → T1 aborted.
Q10
T1: TS=9, requests R(B); last write of B TS=5.
Can T1 read?
A. Yes
B. No
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- Read-after-write allowed since T1 newer than last write → T1 reads successfully.
Q11
T1: TS=6, wants W(A); last write of A TS=6.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 aborted
D. Deadlock
✅ Answer: B
Solution:
- T1 timestamp equals last write → conflict → T1 aborted.
Q12
Which is not true about Timestamp Ordering Protocol?
A. Deadlock-free
B. Uses timestamps to order operations
C. Guarantees recoverable schedules
D. May require waits
✅ Answer: D
Solution:
- TO is non-blocking → transactions never wait → deadlock-free, no waits required.
Q13
T1: TS=5, wants R(A); last write TS(A)=7.
Action?
A. T1 reads successfully
B. T1 aborts
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Read-after-write conflict: T1 older than last write → T1 aborted.
Q14
T1: TS=8, wants W(B); last read TS(B)=6.
Can T1 proceed?
A. Yes
B. No, abort T1
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last read → no conflict → T1 writes successfully.
Q15
Which rule applies for Write-after-Read conflicts in TO?
A. Abort older transaction
B. Abort newer transaction
C. Delay transaction
D. Ignore
✅ Answer: A
Solution:
- Older transaction attempting write after newer read → violates TO → older transaction aborted.
Q16
T1: TS=12, requests R(A); last write TS(A)=10.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 aborted
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed → T1 reads successfully.
Q17
T1: TS=4, wants W(A); last read TS(A)=7.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 aborted
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict: T1 older than last read → T1 aborted.
Q18
Which property is inherent in Timestamp Ordering Protocol?
A. Deadlock-free
B. Cascading aborts free
C. Serializability
D. All of the above
✅ Answer: D
Solution:
- TO protocol → deadlock-free, avoids cascading aborts by aborting conflicting transactions, ensures serializability.
Q19
T1: TS=9, wants W(A); last write TS(A)=7.
Can T1 write?
A. Yes
B. No, abort
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last write → write allowed.
Q20
T1: TS=3, requests R(A); last write TS(A)=5.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 aborted
D. Deadlock
✅ Answer: B
Solution:
- T1 older than last write → violates read-after-write rule → T1 aborted.
Q21
T1: TS=6, requests W(A); last read TS(A)=8.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 aborted
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict: T1 older than last read → violates TO → T1 aborted.
Q22
T1: TS=12, requests R(B); last write TS(B)=10.
Can T1 read?
A. Yes
B. No, abort
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q23
T1: TS=4, requests W(C); last write TS(C)=5.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 aborted
D. Wait
✅ Answer: B
Solution:
- T1 older than last write → violates write-after-write TO rule → T1 aborted.
Q24
Which type of conflict is resolved by aborting the older transaction in TO?
A. Read-after-write
B. Write-after-read
C. Write-after-write
D. Both B and C
✅ Answer: B
Solution:
- In write-after-read, older transaction trying to write after newer read → older aborted.
Q25
T1: TS=8, requests R(A); last write TS(A)=10.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 aborted
D. Wait
✅ Answer: B
Solution:
- T1 older than last write → read-after-write conflict → T1 aborted.
Q26
T1: TS=15, requests W(B); last read TS(B)=12.
Can T1 write?
A. Yes
B. No, abort
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last read → write allowed.
Q27
Which property is ensured inherently by Timestamp Ordering?
A. Deadlock-free
B. Conflict-serializable
C. Cascading-abort-free
D. All of the above
✅ Answer: D
Solution:
- TO protocol → no waits → deadlock-free
- Ensures serializability
- Avoids cascading aborts by aborting conflicting transactions.
Q28
T1: TS=9, requests R(C); last write TS(C)=7.
Can T1 read?
A. Yes
B. No, abort
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed → T1 reads successfully.
Q29
T1: TS=5, wants W(D); last read TS(D)=6.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 aborted
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict: T1 older than last read → T1 aborted.
Q30
T1: TS=11, requests R(B); last write TS(B)=10.
Can T1 read?
A. Yes
B. No
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q31
T1: TS=7, requests W(A); last write TS(A)=7.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 aborted
D. Deadlock
✅ Answer: B
Solution:
- Timestamp equal → violates TO → T1 aborted.
Q32
Which type of operation never waits in TO protocol?
A. Read
B. Write
C. Both read & write
D. None
✅ Answer: C
Solution:
- TO protocol → non-blocking → conflicts resolved via abort → transactions never wait → deadlock-free.
Q33
T1: TS=8, requests R(A); last write TS(A)=12.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 aborted
D. Wait
✅ Answer: B
Solution:
- T1 older than last write → read-after-write conflict → T1 aborted.
Q34
T1: TS=10, wants W(B); last read TS(B)=9.
Can T1 write?
A. Yes
B. No, abort
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last read → write allowed.
Q35
Which rule handles write-after-write conflicts in TO?
A. Abort older transaction
B. Abort newer transaction
C. Delay transaction
D. Ignore conflict
✅ Answer: B
Solution:
- Newer transaction trying to write → older/newer comparison → if timestamp newer, may proceed or older aborted → ensures serializability.
Q36
T1: TS=6, requests R(C); last write TS(C)=8.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 abort
D. Deadlock
✅ Answer: B
Solution:
- T1 older than last write → violates TO → T1 aborted.
Q37
T1: TS=13, requests W(D); last read TS(D)=11.
Can T1 write?
A. Yes
B. No, abort
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last read → write allowed.
Q38
Which property is unique to Timestamp Ordering Protocol compared to 2PL?
A. Deadlock-free
B. Serializability
C. Cascading-abort-free
D. Lock-based
✅ Answer: A
Solution:
- TO is non-locking → deadlock-free by design → unlike 2PL, which may deadlock.
Q39
T1: TS=5, wants W(E); last read TS(E)=7.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 aborted
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict: older transaction → T1 aborted.
Q40
T1: TS=9, requests R(E); last write TS(E)=6.
Can T1 read?
A. Yes
B. No, abort
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q41
T1: TS=7, requests W(A); last read TS(A)=10.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 aborted
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict: older transaction trying to write after newer read → violates TO → T1 aborted.
Q42
T1: TS=12, requests R(B); last write TS(B)=9.
Can T1 read?
A. Yes
B. No, abort
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed → T1 reads successfully.
Q43
T1: TS=6, requests W(C); last write TS(C)=7.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 aborted
D. Wait
✅ Answer: B
Solution:
- Older transaction trying to write after newer write → violates TO → T1 aborted.
Q44
T1: TS=8, requests R(A); last write TS(A)=10.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 aborted
D. Wait
✅ Answer: B
Solution:
- Read-after-write conflict → T1 older than last write → T1 aborted.
Q45
T1: TS=14, requests W(B); last read TS(B)=12.
Can T1 write?
A. Yes
B. No, abort
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last read → write allowed → T1 writes successfully.
Q46
Which property is guaranteed by Timestamp Ordering Protocol?
A. Deadlock-free
B. Conflict-serializable
C. Cascading-abort-free
D. All of the above
✅ Answer: D
Solution:
- TO protocol → non-blocking (deadlock-free), aborts conflicting transactions (cascading-abort-free), ensures serializability.
Q47
T1: TS=5, requests R(D); last write TS(D)=8.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- T1 older than last write → read-after-write conflict → T1 aborted.
Q48
T1: TS=11, requests W(C); last read TS(C)=10.
Can T1 write?
A. Yes
B. No, abort
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last read → write allowed.
Q49
T1: TS=7, requests R(E); last write TS(E)=5.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q50
T1: TS=6, requests W(A); last read TS(A)=9.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict → older transaction → T1 aborted.
Q51
T1: TS=13, requests R(B); last write TS(B)=10.
Can T1 read?
A. Yes
B. No
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed → T1 reads successfully.
Q52
T1: TS=8, requests W(C); last write TS(C)=8.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Deadlock
✅ Answer: B
Solution:
- Timestamp equal → violates TO rule → T1 aborted.
Q53
T1: TS=5, requests R(A); last write TS(A)=7.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Read-after-write conflict → T1 older than last write → T1 aborted.
Q54
T1: TS=10, requests W(B); last read TS(B)=8.
Can T1 write?
A. Yes
B. No, abort
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last read → write allowed → T1 writes successfully.
Q55
Which operation never waits in Timestamp Ordering?
A. Read
B. Write
C. Both read & write
D. None
✅ Answer: C
Solution:
- TO is non-blocking → transactions abort conflicts instead of waiting → deadlock-free.
Q56
T1: TS=7, requests R(D); last write TS(D)=9.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 abort
D. Deadlock
✅ Answer: B
Solution:
- Older read after newer write → T1 aborted.
Q57
T1: TS=14, requests W(E); last read TS(E)=11.
Can T1 write?
A. Yes
B. No, abort
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last read → write allowed → T1 writes successfully.
Q58
T1: TS=6, requests R(C); last write TS(C)=8.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 abort
D. Deadlock
✅ Answer: B
Solution:
- Read-after-write conflict → T1 older → aborted.
Q59
T1: TS=12, requests R(D); last write TS(D)=10.
Can T1 read?
A. Yes
B. No, abort
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q60
T1: TS=5, requests W(A); last read TS(A)=7.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict → older transaction → T1 aborted.
Q61
T1: TS=9, requests W(A); last read TS(A)=12.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 aborted
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict: T1 older than last read → violates TO → T1 aborted.
Q62
T1: TS=13, requests R(B); last write TS(B)=10.
Can T1 read?
A. Yes
B. No, abort
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed → T1 reads successfully.
Q63
T1: TS=7, requests W(C); last write TS(C)=9.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 aborted
D. Wait
✅ Answer: B
Solution:
- Older write after newer write → violates TO → T1 aborted.
Q64
T1: TS=8, requests R(D); last write TS(D)=10.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 aborted
D. Wait
✅ Answer: B
Solution:
- Read-after-write conflict → T1 older than last write → T1 aborted.
Q65
T1: TS=15, requests W(E); last read TS(E)=12.
Can T1 write?
A. Yes
B. No, abort
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last read → write allowed → T1 writes successfully.
Q66
T1: TS=5, requests R(A); last write TS(A)=8.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 abort
D. Deadlock
✅ Answer: B
Solution:
- Older read after newer write → T1 aborted.
Q67
T1: TS=12, requests W(B); last read TS(B)=10.
Can T1 write?
A. Yes
B. No, abort
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last read → write allowed → T1 writes successfully.
Q68
T1: TS=6, requests R(C); last write TS(C)=9.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 abort
D. Deadlock
✅ Answer: B
Solution:
- Read-after-write conflict → older transaction → T1 aborted.
Q69
T1: TS=14, requests R(D); last write TS(D)=11.
Can T1 read?
A. Yes
B. No, abort
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q70
T1: TS=5, requests W(A); last read TS(A)=7.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict → older transaction → T1 aborted.
Q71
T1: TS=9, requests R(B); last write TS(B)=6.
Can T1 read?
A. Yes
B. No, abort
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → T1 reads successfully.
Q72
T1: TS=8, requests W(C); last write TS(C)=8.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Deadlock
✅ Answer: B
Solution:
- Timestamp equal → violates TO → T1 aborted.
Q73
T1: TS=6, requests R(D); last write TS(D)=9.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 abort
D. Deadlock
✅ Answer: B
Solution:
- Older read after newer write → T1 aborted.
Q74
T1: TS=13, requests W(E); last read TS(E)=11.
Can T1 write?
A. Yes
B. No, abort
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last read → write allowed.
Q75
T1: TS=7, requests R(A); last write TS(A)=10.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 abort
D. Deadlock
✅ Answer: B
Solution:
- Read-after-write conflict → older → T1 aborted.
Q76
T1: TS=10, requests W(B); last read TS(B)=8.
Can T1 write?
A. Yes
B. No, abort
C. T2 abort
D. Wait
✅ Answer: A
Solution:
- T1 newer than last read → write allowed → T1 writes successfully.
Q77
Which property is unique to TO compared to 2PL?
A. Deadlock-free
B. Serializability
C. Cascading-abort-free
D. Lock-based
✅ Answer: A
Solution:
- TO is non-locking → deadlock-free by design.
Q78
T1: TS=5, requests W(C); last read TS(C)=7.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict → T1 aborted.
Q79
T1: TS=12, requests R(D); last write TS(D)=10.
Can T1 read?
A. Yes
B. No, abort
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q80
T1: TS=6, requests W(E); last write TS(E)=9.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Older write after newer write → T1 aborted.
Q81
T1: TS=8, requests R(A); last write TS(A)=7.
Can T1 read?
A. Yes
B. No
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q82
T1: TS=5, requests W(B); last read TS(B)=8.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict → older → T1 aborted.
Q83
T1: TS=14, requests R(C); last write TS(C)=10.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q84
T1: TS=7, requests W(D); last read TS(D)=9.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict → T1 older → T1 aborted.
Q85
T1: TS=11, requests R(E); last write TS(E)=10.
Can T1 read?
A. Yes
B. No
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q86
T1: TS=6, requests W(A); last write TS(A)=9.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Older write after newer write → T1 aborted.
Q87
T1: TS=13, requests R(B); last write TS(B)=11.
Can T1 read?
A. Yes
B. No
C
. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q88
T1: TS=5, requests W(C); last read TS(C)=7.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict → T1 aborted.
Q89
T1: TS=12, requests R(D); last write TS(D)=10.
Can T1 read?
A. Yes
B. No
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q90
T1: TS=6, requests W(E); last write TS(E)=9.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Older write after newer write → T1 aborted.
Q91
T1: TS=8, requests R(A); last write TS(A)=7.
Can T1 read?
A. Yes
B. No
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q92
T1: TS=5, requests W(B); last read TS(B)=8.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict → T1 aborted.
Q93
T1: TS=14, requests R(C); last write TS(C)=10.
Action?
A. T1 reads successfully
B. T1 aborted
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q94
T1: TS=7, requests W(D); last read TS(D)=9.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict → T1 older → T1 aborted.
Q95
T1: TS=11, requests R(E); last write TS(E)=10.
Can T1 read?
A. Yes
B. No
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q96
T1: TS=6, requests W(A); last write TS(A)=9.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Older write after newer write → T1 aborted.
Q97
T1: TS=13, requests R(B); last write TS(B)=11.
Can T1 read?
A. Yes
B. No
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q98
T1: TS=5, requests W(C); last read TS(C)=7.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Write-after-read conflict → T1 aborted.
Q99
T1: TS=12, requests R(D); last write TS(D)=10.
Can T1 read?
A. Yes
B. No
C. T2 abort
D. Deadlock
✅ Answer: A
Solution:
- T1 newer than last write → read allowed.
Q100
T1: TS=6, requests W(E); last write TS(E)=9.
Action?
A. T1 writes successfully
B. T1 aborted
C. T2 abort
D. Wait
✅ Answer: B
Solution:
- Older write after newer write → T1 aborted.
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