Conflict serializable very difficult GATE QUESTION 2017,should have come for atleast 10 marks,how can they ask this for 2 marks?


#1

T1: r1(X)w1(X)r1(Y)w1(Y)

T2 : r2(Y)w2(Y)r2(Z)w2(Z)

where ri(V) denotes a read operation by transaction Ti on a variable V and wi(V) denotes a write operation by transaction Ti on a variable V. The total number of conflict serializable schedules that can be formed by T1 and T2 is ______


#2


#3

Hi thanks for sharing answer !
i have one doubt why haven’t u taken into consideration conflicting action of R2(y) and w1(y).


#4

see 2nd conflicting action. It’s there. Try to go through the solution once more. You will get it. Try to generate the permutations that are counted actually. You will get the solution.


#5

In exam how to deal with? this when i move in positive way of solving by tree structure,it consume lot of time,above approach works in a complement way which is time reducing factor.


#6

@Vinay96 why did u not considered first
W1(y), then W2(y) and then after R1(y) , because that is also a conflict. Why only u considered 2 conflict actions??