Operating System MCQ and Answers – Atomic Transactions

These Operating System MCQ and Answers – Atomic Transactions are asked in various examinations including BCA, MCA, GATE, and other tests. The questions based on the below Operating System MCQ and Answers – Atomic Transactions test your basic knowledge of MCQs on the topic of Operating Systems and the level of comprehension and grasp that you hold.

Operating System MCQ and Answers – Atomic Transactions

1. Write ahead logging is a way ____________

a) to ensure atomicity

b) to keep data consistent

c) that records data on stable storage

d) all of the mentioned

Answer: d

2. In the write ahead logging a _____________ is maintained.

a) a memory

b) a system

c) a disk

d) a log record

Answer: d

3. An actual update is not allowed to a data item ____________

a) before the corresponding log record is written out to stable storage

b) after the corresponding log record is written out to stable storage

c) until the whole log record has been checked for inconsistencies

d) all of the mentioned

Answer: a

4. The undo and redo operations must be _________ to guarantee correct behaviour, even if a failure occurs during recovery process.

a) idempotent

b) easy

c) protected

d) all of the mentioned

Answer: a

5. The system periodically performs checkpoints that consists of the following operation(s) ____________

a) Putting all the log records currently in main memory onto stable storage

b) putting all modified data residing in main memory onto stable storage

c) putting a log record onto stable storage

d) all of the mentioned

Answer: d

6. Consider a transaction T1 that committed prior to checkpoint. The <T1 commits> record appears in the log before the <checkpoint> record. Any modifications made by T1 must have been written to the stable storage either with the checkpoint or prior to it. Thus at recovery time ____________

a) There is a need to perform an undo operation on T1

b) There is a need to perform a redo operation on T1

c) There is no need to perform an undo and redo operation on T1

d) All of the mentioned

Answer: c

7. Serializable schedules are ones where ____________

a) concurrent execution of transactions is equivalent to the transactions executed serially

b) the transactions can be carried out one after the other

c) a valid result occurs after execution transactions

d) none of the mentioned

Answer: a

8. A locking protocol is one that ____________

a) governs how locks are acquired

b) governs how locks are released

c) governs how locks are acquired and released

d) none of the mentioned

Answer: c

9. The two phase locking protocol consists of ____________

a) growing & shrinking phase

b) shrinking & creation phase

c) creation & growing phase

d) destruction & creation phase

Answer: a

10. The growing phase is a phase in which?

a) A transaction may obtain locks, but does not release any

b) A transaction may obtain locks, and releases a few or all of them

c) A transaction may release locks, but does not obtain any new locks

d) A transaction may release locks, and does obtain new locks

Answer: a

11. The shrinking phase is a phase in which?

a) A transaction may obtain locks, but does not release any

b) A transaction may obtain locks, and releases a few or all of them

c) A transaction may release locks, but does not obtain any new locks

d) A transaction may release locks, and does obtain new locks

Answer: c

12. A collection of instructions that performs a single logical function is called ____________

a) transaction

b) operation

c) function

d) all of the mentioned

Answer: a

13. A terminated transaction that has completed its execution successfully is ____________ otherwise it is __________

a) committed, destroyed

b) aborted, destroyed

c) committed, aborted

d) none of the mentioned

Answer: c

14. The state of the data accessed by an aborted transaction must be restored to what it was just before the transaction started executing. This restoration is known as ________ of transaction.

a) safety

b) protection

c) roll – back

d) revert – back

Answer: c

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