ACID properties: Does an ACID transaction stand for atomic, consistent, isolated, and durable (the four fundamental guarantees)?

Introduction / Context:
ACID summarizes the essential guarantees of reliable transaction processing. This question checks recognition of the four ACID properties and their meanings in practice.

Given Data / Assumptions:

• Atomic: all-or-nothing.
• Consistent: preserves database invariants.
• Isolated: concurrent execution does not cause interference beyond the chosen isolation level.
• Durable: committed effects persist despite failures.

Concept / Approach:
ACID is independent of specific storage engines or architectures. Whether centralized or distributed (with 2PC/3PC, Paxos/Raft-backed logs), ACID describes the transactional contract offered to applications, though implementations may differ in strictness and performance.

Step-by-Step Solution:

Verification / Alternative check:
Consult any DBMS fundamentals text; the acronym expansion is uniform across vendors and academia.

Why Other Options Are Wrong:

• Limiting ACID to distributed systems or NoSQL is incorrect. Many NoSQL systems are non-ACID by default; many RDBMS are ACID.
• “Incorrect” conflicts with the accepted definition.

Common Pitfalls:
Confusing “consistency” in ACID with “consistency” in CAP; they are different concepts.

Final Answer:
Correct