Once the DBMS informs the user that a transaction has been successfully completed, its effect should persist even if the system crashes before all its changes are reflected on disk. This property is called
Answer
(A)
Explanation
This is durability, the D in ACID: once a transaction has committed, its changes must survive any later failure. The DBMS ensures it by forcing the transaction's log records to stable storage before it reports the commit, so after a crash the recovery manager can redo committed changes that had not yet reached the data pages on disk.
- Atomicity is all-or-nothing execution: a transaction's changes are applied completely or not at all.
- Consistency means a transaction takes the database from one valid state to another.
- Isolation means concurrent transactions do not see each other's intermediate results.
Answer: A