# nptel

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Which of the following statement is correct ?
1. 2 phase locking protocol does not suffer with problem of cascading rollback
2. Strict 2 phase protocol never results in deadlock
3. In strict 2 phase protocol, restriction of releasing exclusive locks until commit ensures no cascading rollbacks
4. Time-stamp ordering protocol can generate non-recoverable schedules
1

1. 2 phase locking protocol does not suffer with problem of cascading rollback : False( it must be strict 2pl.)
2. Strict 2 phase protocol never results in deadlock. False ( It can be in deadlock)
3. In strict 2 phase protocol, restriction of releasing exclusive locks until commit ensures no cascading rollbacks. True
4. Time-stamp ordering protocol can generate non-recoverable schedules. False ( always recoverable)

0
4 .if timestamp is strict then it only give recoverable schedule as they are cascadless. but, Basic time stamp only ensure serilizablity not recoverable it may be non-recoverable.

## Related questions

1
126 views
Which of the following transaction(s) follow 2-phase locking protocol? lock1(a)read1(a)lock2(b)write2(b)lock1(c)unlock2(b)unclock1(c)lock2(c)unlock1(a) lock1(a)lock1(b)unlock1(a)lock2(a)write2(a)unlock2(a)unlock1(b) lock1(a)lock2(b)lock1(c)lock3(d)unlock2(b)lock3(b)unlock1(a)unlock3(d)unlock1(c)lock3(c) 1. Only 1 2. Only 2 3. Only 1 and 3 4. None of them