Which property ensures that concurrent transactions do not interfere with each other?

• A. Durability
• B. Isolation
• C. Consistency
• D. Atomicity

Answer: (B)

Isolation is the property that ensures concurrent transactions do not interfere with each other, making the system behave as if each transaction runs in its own private environment or serially. This means the effects of one transaction aren’t visible to others until it commits, and the database enforces rules to prevent reads or writes from seeing partial, intermediate results. This vigilance stops issues like dirty reads, non-repeatable reads, and phantom reads, keeping data consistent from the perspective of each running transaction. The other properties aren’t about how transactions interact concurrently: durability is about preserving committed results after system failures, atomicity is about a transaction as a whole either succeeding or failing, and consistency is about the database’s invariants being preserved overall.