Total of 5 transactions are here.
Let us try to see any pattern from
1. Initial reads:
T1 is reading A , which no one is writing.
T3 is reading D, which no one is writing.
// no more initial reads.
What can we say yet? anyone can come at anytime.
2. Updated read:
T2 and T4 are reading B being written by T1. // T1-->{T2,T4}
T5 is reading C from T2. // T2-->T5
T5 is reading E from T4. // T4-->T5
3. Final writes:
T1-->T5 (for B only)
------------------------------
T1-->{T2,T4}-->T5
We can arrange above achedule in 2! ways.
T3 can be placed anywhere // 5 places would be there.
Total schedules are 2! *5 =10.
