DA0-002 Data Concepts and Environments Practice Question
A data engineer needs to extract data from a REST API and load it into a data warehouse. The data is received in JSON format. Which data type best describes JSON?
⚠ Common exam trap
A common mix-up: candidates confuse the presence of structure (keys and values) with being fully structured, overlooking that JSON lacks a fixed schema and allows variability, which places it in the semi-structured category.
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
✓
Semi-structured
JSON (JavaScript Object Notation) is classified as a semi-structured data type because it uses a flexible, self-describing schema with key-value pairs and nested structures, but does not enforce a rigid tabular schema like relational databases. In the context of extracting data from a REST API, JSON allows for varying fields and hierarchical data, which aligns with the semi-structured category.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Transactional
Why it's wrong here
Transactional refers to a type of database (OLTP), not a data type.
- ✓
Semi-structured
Why this is correct
JSON is semi-structured as it has organizational properties (key-value pairs) but no rigid schema.
- ✗
Unstructured
Why it's wrong here
Unstructured data lacks a predefined data model; JSON has structure with keys and values.
- ✗
Structured
Why it's wrong here
Structured data has a fixed schema, typically in rows and columns; JSON allows flexible schemas.
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Written by Johnson Ajibi, MSc IT Security
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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.