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Transactions T1 (timestamp 10) and T2 (timestamp 20) run under basic timestamp ordering. T2 has already read the data item X. Now T1 issues write(X). What happens?
- AT1's write is allowed and X is updated
- BT1 is rolled back and restarted with a new timestamp
- CT2 is rolled back
- DT1 waits until T2 commits
Correct answer: B