In a database system, let TS(T1) and TS(T2) be the timestamps of transactions T1 and T2 respectively. W-t(X) denotes the largest timestamp of any transaction that executed write(X) successfully and R-t(X) denotes the largest timestamp of any transaction that executed read(X) successfully. Which of the following is False?
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1
If transaction T1 issues read(X) operation and TS(T1) < W-t(X) then T1 is rolled back.
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2
If transaction T1 issues read(X) operation and TS(T1) > W-t(X) then write operation is executed.
Correct Answer
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3
If transaction T1 issues write(X) operation and TS(T1) < W-t(X) then T1 is rolled back.
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4
All of the above.
Can anyone plz explain the working and what approach to take while solving these type of questions?
