Question : Which of the following best describes the main advantage of the Thomas Write Rule over basic timestamp ordering?
Solution :
Correct Answer : Reduces unnecessary transaction aborts
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Question : Why is the Thomas Write Rule considered more flexible than the basic timestamp ordering protocol?
Solution :
Correct Answer : It ignores certain obsolete write operations
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Question : Which type of serializability is always ensured by the Thomas Write Rule?
Solution :
Correct Answer : View serializability
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Question : Which of the following is NOT a characteristic of validation-based protocol?
Solution :
Correct Answer : Requires locking of data items
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Question : Which scenario leads to poor performance of validation-based protocols?
Solution :
Correct Answer : Frequent conflicts among transactions
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Question : Why is the timestamp of the validation phase often used for serialization order?
Solution :
Correct Answer : Because validation phase decides commit or rollback
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Question : In a validation-based protocol, which phase determines whether a transaction will commit or rollback?
Solution :
Correct Answer : Validation Phase
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Question : Why are older transactions given higher priority in Timestamp Ordering?
Solution :
Correct Answer : To maintain serializability based on timestamp order
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Question : Which statement is NOT correct about Timestamp Ordering Protocol?
Solution :
Correct Answer : It always produces recoverable schedules
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Question : Which of the following ensures that the Timestamp Ordering Protocol is deadlock-free?
Solution :
Correct Answer : Transactions are rolled back instead of waiting
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Question : In 2PL, the point where a transaction has acquired all required locks and enters shrinking phase is called:
Solution :
Correct Answer : Lock point
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Question : Which of the following problems can still occur in basic lock-based protocols (including 2PL)?
Solution :
Correct Answer : Deadlock
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Question : What is the main difference between 2PL and Strict 2PL?
Question : Which protocol ensures deadlock prevention by requesting all locks before execution begins?
Solution :
Correct Answer : Pre-claiming Lock Protocol
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Question : Which of the following statements about Two-Phase Locking (2PL) is correct?
Solution :
Correct Answer : No locks can be released in the growing phase
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Question : Which concurrency control technique allows transactions to proceed without locks initially and checks conflicts at commit time?
Solution :
Correct Answer : Optimistic concurrency control
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Question : Which of the following statements about Two-Phase Locking (2PL) is correct?
Solution :
Correct Answer : Once a lock is released, no new lock can be acquired
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Question : Which anomaly is NOT possible under Serializable isolation level?
Solution :
Correct Answer : All of the above
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Question : In timestamp ordering protocol, a transaction is rolled back if:
Solution :
Correct Answer : Its timestamp is smaller than the write timestamp of the data item
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Question : Which of the following schedules is recoverable but not cascadeless?
Solution :
Correct Answer : A schedule where a transaction reads uncommitted data but commits after the writer commits
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