Statement I: Conservative 2PL is a deadlock-free protocol. Statement II: Thomas's write rule enforces conflict serializability. Statement III: Timestamp ordering ensures serializability based on the order of transaction timestamps. Which is correct?

1. AStatements I and II true, Statement III false
2. BStatements I and III true, Statement II false
3. CStatements I and II false, Statement III true
4. DStatements I, II and III true

Pick an option to check yourself, or open the answer below.

Show answer & explanation

Correct answer: B. Statements I and III true, Statement II false

Explanation

Conservative 2PL takes all locks before starting, so it cannot deadlock (I true). Thomas's write rule allows view-serializable schedules that are not conflict-serializable (II false). Timestamp ordering serializes in timestamp order (III true).