DA0-002 Data Concepts and Environments Practice Question
A data engineer is designing a system to store raw sensor data from thousands of IoT devices. The data will be used later for various analytics projects, but the schema is not yet defined. Which storage solution is most appropriate?
⚠ Common exam trap
DA0-002 often tests the distinction between schema-on-write (data warehouse) and schema-on-read (data lake), so candidates who pick a data warehouse because it 'stores data for analytics' miss the requirement that the schema is not yet defined.
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
✓
Data lake
A data lake is designed to store raw, unprocessed data in its native format without requiring a predefined schema, which is exactly what is needed for IoT sensor data whose schema is not yet defined. It supports schema-on-read, allowing analytics projects to interpret the data later as requirements evolve. This makes it the most appropriate choice for storing diverse, high-volume raw data for future analytics.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Data lake
Why this is correct
A data lake stores raw data in its native format without requiring a predefined schema, satisfying the undefined-schema constraint. It handles high-volume ingestion from thousands of IoT devices and supports diverse downstream analytics, including structured, semi-structured and unstructured data, which a schema-on-write warehouse cannot accommodate.
- ✗
Data mart
Why it's wrong here
A data mart holds curated, modelled data for a specific business function with a defined schema, so it cannot absorb undefined raw sensor feeds. It would be the right choice once analytics requirements are known and a subject-specific subset must be served to one department.
- ✗
Data warehouse
Why it's wrong here
A data warehouse stores structured, schema-on-write data transformed for reporting, so raw undefined sensor data cannot be loaded without prior modelling. It would be correct when the schema is settled and cleansed data must support consistent BI queries across the enterprise.
- ✗
Relational database
Why it's wrong here
A relational database enforces a fixed schema and typed columns at insert time, so undefined sensor payloads cannot be stored without redesign. It would be correct where entities and relationships are known and ACID transactions with referential integrity are required.
Go deeper
Related to this question
About these practice questions
One of 1,004 original DA0-002 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. 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.