DA0-002 Data Concepts and Environments Practice Question
A company is designing a database for an e-commerce application that requires high transaction throughput and must guarantee that each transaction is processed atomically. Which property of ACID ensures that a transaction is either fully completed or not executed at all?
⚠ Common exam trap
The trap here is that candidates conflate Consistency with Atomicity because both sound like 'the transaction is correct' — but Consistency is about rule/constraint preservation, while Atomicity is specifically about all-or-nothing execution.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
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Atomicity
Atomicity is the ACID property that guarantees a transaction is treated as a single indivisible unit — either all of its operations commit or none of them do. If any statement in the transaction fails, the entire transaction is rolled back, leaving the database in its pre-transaction state. This is the 'all-or-nothing' guarantee that the question describes.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
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Atomicity
Why this is correct
Atomicity treats each transaction as an indivisible unit: every operation commits together or the whole transaction rolls back, leaving no partial state. This precisely satisfies the stem's requirement that a transaction is either fully completed or not executed at all, unlike consistency, isolation or durability.
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Isolation
Why it's wrong here
Isolation governs how concurrent transactions interleave and see each other's uncommitted changes, preventing dirty reads and lost updates. It would be correct when the requirement is controlling interference between simultaneous transactions, not guaranteeing all-or-nothing execution of a single transaction.
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Durability
Why it's wrong here
Durability guarantees that committed changes survive system failure by persisting to non-volatile storage. It would be correct when the concern is protecting completed transactions against crashes or power loss, not ensuring a transaction either completes fully or has no effect.
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Consistency
Why it's wrong here
Consistency ensures a transaction moves the database from one valid state to another, honouring constraints and invariants. It would be correct when the requirement is preserving declared rules and relationships, not guaranteeing that a transaction executes entirely or not at all.
About these practice questions
Courseiva writes every DA0-002 question from scratch — 1,004 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CompTIA exam blueprint
This DA0-002 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DA0-002 exam.