Assignment Instructions

Consider the following schedule S: $($R$1($X$)$ means T$1$ read X$,$ W$2($Y$)$ means T$2$ write Y$)$

R$1($X$),$ W$2($Y$),$ W$2($X$),$ W$3($Y$),$ W$1($Y$),$ Commit T$1,$ Commit T$2,$ Commit T$3.$

Determine whether $S$ is: conflict$-$serializable.

For each of the following concurrency control mechanisms, describe how the concurrency control mechanism handles S$.$

a$.$ Strict $2$PL with deadlock detection. $($show the waits$-$for graph$)$

b$.$ Timestamping.

Note: for the deadlock detection, you need to draw waits$-$for graph to show whether there is a deadlock. $($if there is a cycle in

the graph, it means deadlock happened.$)$