Difficulty: Easy
Correct Answer: Correct
Explanation:
Introduction / Context:
Transactions are the cornerstone of reliable database operations. The ACID properties (Atomicity, Consistency, Isolation, Durability) formalize expectations for correctness and recoverability. This question checks understanding of the “all-or-none” nature of transaction execution in relational systems.
Given Data / Assumptions:
Concept / Approach:
Atomicity means that a transaction’s operations are indivisible: either every intended change is committed, or none are. Consistency ensures defined constraints hold before and after execution. Isolation keeps concurrent transactions from interfering in a way that violates serial equivalence. Durability guarantees that once committed, changes survive failures. The provided statement matches the atomicity perspective: all-or-none changes preserve validity when combined with appropriate constraints and business rules.
Step-by-Step Solution:
Verification / Alternative check:
Simulate a funds transfer: debit one account and credit another. If one update fails, rolling back both preserves consistency. Committing only one side would break invariants, illustrating why atomicity is essential.
Why Other Options Are Wrong:
Common Pitfalls:
Relying on autocommit for multi-step processes; forgetting to handle errors and thus leaving partial updates committed inadvertently.
Final Answer:
Correct
Discussion & Comments