Consider the following transaction schedules For each one de

Consider the following transaction schedules. For each one, determine if the schedule is conflict serializable and determine the equivalent serial schedules. Please note that there may be several equivalent serializable schedules and you should determine all of them.
a) T1: R(X); T3: R(X); T1: W(X); T2: R(X); T3: W(X)
b) T3: R(X); T2: R(X); T3: W(X); T1: R(X); T1: W(X)

Solution

total schedule = 6!/2!*2!*2! = 90
and every schedule is conflict equal schedule because no cycle in any precedence graph ..
by symmetry each serial schedule must have equal no of conflict schedule..
der are 90 schedule and 3! serial schedule..
T1 ----> T2 ----> T3 is one out of 6 serial schedule.
so no ofconflict equal schedule which is equal to T1 ----> T2 ----> T3
= 90/6 = 15