Consider the following schedules and determine whether the schedule is conflict serializable. If the schedule is conflict serializable, write the conflict equivalent serial schedule of transactions. If the schedule does not conflict serializable, identify a set of conflicting actions that prevent it from being conflict serializable
S₁ = R₁(A)W₂(B)R₂(A)W₁(B)W₃(B)W₁(C)R₃(B)W₁(A)
S₂ = W₂(C)R₁(A)W₃(B)R₁(C)R₃(B)R₃(A)W₁(B)
S₃ = R₃(B)R₂(A)R₁(A)R₂(C)W₃(A)W₂(B)W₁(C)
S₄ = W₁(A)W₂(B)W₁(B)W₂(A)
Which of the following schedule are conflict serializable?
(A) S₁ and S₃
(B) S₁ and S₂
(C) S₂ and S₄
(D) S₂ and S₃


Answer: (B)

Explanation: S₁, and S₂ is conflict serializable with equivalent serial schedule T₂T₁T₃ and ( T₃T₂T₁ but S₃ or T₂T₃T₁ but S₃and S₄ is not conflict serializable due to R₃(B) before W₃(B) and R₂(A) before W₃(A) or { R₂(C) before W₁(A) and R₁(A) before W₃(A) R₃(B) before W₃(B) }W₁(A) before W₂(A) and W₂(B) before W₁(B) respectively.
So, option (B) is correct.

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