Of which ACID semantic is this an example?

A bank has a system that manages financial transactions.

When transferring money between accounts, the system must never retrieve a value for the source account that reflects the balance before the transfer and a value for the destination account that reflects the balance after the transfer.

Of which ACID semantic is this an example?
A . atomicity
B. isolation
C. durability
D. consistency

View Answer

Answer: B

Explanation:

Isolation. See course material:

o concurrent transactions cannot interfere with one another, and must result in a consistent database state.

o For example, while the transaction to transfer funds from one account to another is in-process, another transaction that checks the balance of these accounts must return consistent results – the balance-checking transaction can’t retrieve a value for one account that reflects the balance before the transfer, and a value for the other account that reflects the balance after the transfer.