Practice mode DBMS and SQL

Under the wait-die deadlock prevention scheme, an older transaction T1 requests a lock held by a younger transaction T2. What happens?

Correct answer B. T1 waits for T2

Explanation

Wait-die is non-preemptive and uses timestamps: an older requester is allowed to wait for a younger holder, while a younger requester that wants a lock held by an older transaction dies (is rolled back) and restarts with its original timestamp. Rolling back the younger holder is the wound-wait rule, which is preemptive. Both schemes avoid deadlock because waits only go in one age direction.

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Under the wait-die deadlock prevention scheme, an older transaction T1 requests a lock held by a younger transaction T2. What happens?

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Under the wait-die deadlock prevention scheme, an older transaction T1 requests a lock held by a younger transaction T2. What happens?

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