conflict serializability

Question

Consider a schedule
S: r₁(A); W₁(B); W₁(C); r₂(A); W₂(B); W₂(C); abort₂; r₃(A); W₃(B); W₃(C); C₁; C₃ 

How many conflict equivalent serial schedules are possible for the given schedule ?

Answer 1

$T1\rightarrow t2\rightarrow t3$

Only one such conflict serial schedule is possible and conflict equal serial schedule is the topological order of the precedence graph.

Comments

actually this answer is not given.

---

answer is given 3.

---

But how 3 ??

Answer 2

@resilient. T2 is performing abort in between. So, we can consider the non-conflicting operations only before 'abort' operatioon.

1st schedule: Given serial schedule

2nd schedule: W₁(c) and W₂(B) can be swapped to produce conflict equivalent schedule.

So, I am getting only 2 schedules.