Question

Q2. Check whethe.r the given schedule S is conflict serializable or not? If yes, then Draw a precedence graph for it and give valid serial schedules possible using topological sort. S : R1(A) , R2(A) , R1(B) , R2(B) , R3(B) , W1(A) , W2(B)

Answer 1

List all the conflicting operations and determine the dependency between the transactions-

• R₃(B), W₂(B) (T₃ → T₂)
• _R2(A), W₁(A) (T₂ → T₁)
• R₁(B), W₂(B) (T₁ → T₂)

Precedence Graph is:

There is a circle in the precedence graph, thus schedule S is not serializable.