1 votes 1 votes Which of the following schedules are conflicts serializable? S1: $r1$ $\left ( A \right )$, $r1$$\left ( B \right )$, $w2$$\left ( A \right )$, $r3$ $\left ( A \right )$, $w1$$\left ( B \right )$, $w3$ $\left ( A \right )$, $r2$ $\left ( B \right )$, $w2$$\left ( B \right )$ S2 : $r1$$\left ( A \right )$, $r2$$\left ( A \right )$, $r3$ $\left (B \right )$, $w1$$\left ( A \right )$, $r2$ $\left ( C \right )$, $r2$ $\left (B \right )$, $w2$ $\left (B \right )$, $w1$$\left ( C \right )$ S3: $w3$$\left ( A \right )$ , $r1$ $\left ( A \right )$, $w1$ $\left (B \right )$, $r2$$\left (B \right )$, $w2$ $\left ( C \right )$, $r3$, $\left ( C \right )$ $S1,S3$ only $S2,S3$ only $S1,S2$ only $S1, S2, S3$ GATE tbb-mockgate-2 databases transaction-and-concurrency conflict-serializable + – Bikram asked Jan 24, 2017 • retagged Sep 12, 2020 by ajaysoni1924 Bikram 371 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
Best answer 2 votes 2 votes S1: Precedence graph , No cycle: So conflict serializable. S2: Precedence graph , No cycle: Conflict serializable. S3: Precedence graph , Cycle: Not conflict serializable Bikram answered Jan 24, 2017 • selected Feb 1, 2017 by Bikram Bikram comment Share Follow See all 4 Comments See all 4 4 Comments reply Tendua commented Jan 24, 2017 reply Follow Share Think C does not have a cycle 0 votes 0 votes Bikram commented Jan 25, 2017 reply Follow Share S3 does have a cycle so it is not conflict serializable , option C is correct. 0 votes 0 votes rohan_a commented Jan 21, 2018 reply Follow Share where is the cycle in s3 0 votes 0 votes mehul vaidya commented May 24, 2019 reply Follow Share cycle in 3rd transaction is as follow w3(A) -> r1(A) w1(B) -> r2(B) w2(C) -> r3(C) 3 -> 1 1 -> 2 2 -> 3 0 votes 0 votes Please log in or register to add a comment.