consider the following schedule:

Question

S: R₁(x), W₂(x), R₂(x), R₃(x), W₃(x)

If the above schedule S is conflict equal to S' then find S' ?

a)   R₁(x),  R₃(x), W₂(x), R₂(x), W₃(x)

b)   R₁(x), R₂(x), R₃(x), W₂(x), W₃(x)

c)    R₁(x), R₂(x), W₂(x), W₃(x), R₃(x)

d) none

Comments

precedence graphs of S and (c) are equal

But transaction set T₂ of S is  W(x) R(x)

                             T₂ of (c) is R(x)W(x)

Are these  transaction sets same??

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As the R2(X) after W2(X) is of no use ( i.e no write by T2 after this read ) hence u can imagine this to be equivalent with R2(X) follwed by W2(X) .

Then answer is C

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i think we cannot assume like that....As the R2(X) after W2(X) is of no use ( i.e no write by T2 after this read ) 

Answer 1

Ans should be C

because, for A and B we can easily find that they are not possible.

in C last conflict is W(x)->R(x) conflict while last conflict in S is R(x)->W(x) conflict, which are not same in order. But all conflicts in sets of S and C are same. so we can say they are conflict equal, but order is not same therefore they are not conflict equivalent.

Answer 2

The answer is described here.