Required Properties of a Transaction(Cont.) Isolation requirement-if between steps 3 and 6(of the fund transfer transaction),another transaction T2 is allowed to access the partially updated database,it will see an inconsistent database (the sum A B will be less than it should be). T1 T2 1.read(A) 2.A=A-50 3.write(A) read(A),read(B),print(A+B) 4.read(B) 5.B:=B+50 6.write(B Isolation can be ensured trivially by running transactions serially That is,one after the other. However,executing multiple transactions concurrently has significant benefits,as we will see later. Database System Concepts-6th Edition 14.6 @Silberschatz,Korth and SudarshanDatabase System Concepts - 6 14.6 ©Silberschatz, Korth and Sudarshan th Edition Required Properties of a Transaction (Cont.) Isolation requirement — if between steps 3 and 6 (of the fund transfer transaction) , another transaction T2 is allowed to access the partially updated database, it will see an inconsistent database (the sum A + B will be less than it should be). T1 T2 1. read(A) 2. A := A – 50 3. write(A) read(A), read(B), print(A+B) 4. read(B) 5. B := B + 50 6. write(B Isolation can be ensured trivially by running transactions serially That is, one after the other. However, executing multiple transactions concurrently has significant benefits, as we will see later