This document discusses three transaction schedules for withdrawing money from an ATM and evaluates which schedules are serializable. Schedule A is not serializable as T1's withdrawal of $250 occurs after T2 reads the balance but before T2's withdrawal of $50, violating atomicity. Schedule B is serializable as both transactions read the original balance and write changes independently without interfering with each other. Schedule C is also serializable as the transactions again read the original balance and write changes in a non-conflicting order.
5. Transactions. Consider an ATM system. We have 2 transactions. T1 .pdf
1. 5. Transactions. Consider an ATM system. We have 2 transactions. T1: withdraw $50 and 2 :
withdraw $250. We consider concurrent executions of the transactions. Which schedule(s) is
(are) serializable? Explain why. (a) T2 reads the balance. T1 reads the balance. T2 withdraw $50.
T1 withdraw $250. (b) T2 reads the balance. T2 withdraw $250. T1 reads the balance. T1
withdraw $50. (c) T2 reads the balance. T1 reads the balance. T1 withdraw $250.
