View serializability for B.SC. IT SEM-IV
View serializability
•The schedules S and S’ are said to be view equivalent if three conditions are met :-
–If transaction Tireads Q in schedule S then must also reads in S’
–If transaction Tiexecutes reads(Q) in S schedule and if that value was produced by a write(Q) then the read(Q) operations of transaction Timust, in schedule S’ also read the value of Q that was produced by the same write(Q).
–The transfer (if any) that perform the find write(Q) operation in S, must perform the find write(Q) operation in S’