DP-900 Describe core data concepts Practice Question
A company stores customer records in a relational database table with fixed columns (CustomerID, Name, Email). They also store product reviews as JSON documents that may contain varying fields such as Rating, Comment, and optional Tags. Additionally, they store product images as JPEG files. Which of the following correctly orders these data types from most structured to least structured?
⚠ Common exam trap
A common mix-up: candidates confuse semi-structured JSON with unstructured data, or assume that all data with a format (like JPEG headers) is structured, but the key distinction is schema rigidity and queryability.
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
✓
Relational table, JSON documents, image files
Relational tables enforce a fixed schema with predefined columns and data types, making them the most structured. JSON documents have a flexible schema where fields like Tags are optional, placing them in the middle. Image files are binary blobs with no inherent structure, making them the least structured. Option B correctly orders these from most structured (relational table) to least structured (image files).
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
JSON documents, relational table, image files
Why it's wrong here
This arrangement erroneously places JSON documents ahead of relational tables in a most-to-least structured hierarchy. Relational tables have a fixed schema with data types, primary keys, and referential integrity, giving them maximum structure, whereas JSON documents support schema-less flexible objects with nested arrays and variable keys. Since JSON is semi-structured, it must appear after relational tables but before unstructured image files.
When this WOULD be correct
If the question asked to order data types from least structured to most structured, then option A (JSON documents, relational table, image files) would be correct, as JSON is semi-structured, relational is structured, and images are unstructured, but reversed order.
- ✓
Relational table, JSON documents, image files
Why this is correct
Relational tables enforce a rigid schema with predefined columns, data types, and constraints, making them the most structured form. JSON documents use key-value pairs and nested objects but permit varying fields across documents, classifying them as semi-structured. Image files are raw binary streams with no inherent schema or semantic structure, therefore unstructured. This ordering correctly progresses from highest to lowest structural organization.
- ✗
Image files, relational table, JSON documents
Why it's wrong here
This sequence incorrectly begins with image files, which are binary blobs lacking any metadata or row-column structure, thus the least structured category. It then jumps to relational tables, which are actually the most structured due to enforced schema and integrity constraints, before listing JSON documents, whose flexible schema-based organization places them in between. The proper ascending order of structure is image files, JSON documents, then relational tables.
When this WOULD be correct
If the question asked to order data types from least structured to most structured, then 'image files, relational table, JSON documents' would be correct, as images are unstructured, relational tables are structured, and JSON is semi-structured.
- ✗
Relational table, image files, JSON documents
Why it's wrong here
This ordering correctly starts with relational tables, but then places image files before JSON documents, inverting their structural complexity. Image files are just encoded pixel or sound data with no queryable entities, making them unstructured, while JSON documents contain hierarchical key-value pairs that can be parsed and queried, qualifying as semi-structured. Therefore JSON should precede image files in a descending structure ranking.
When this WOULD be correct
If the question asked to order data types from least to most structured, then relational table (most structured) would be last, image files (least structured) first, and JSON documents in the middle, making D correct.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The DP-900 exam frequently reuses these exact scenarios with slightly different constraints.
✓Relational table, JSON documents, image filesCorrect answer▾
Why this is correct
Relational tables enforce a rigid schema with predefined columns, data types, and constraints, making them the most structured form. JSON documents use key-value pairs and nested objects but permit varying fields across documents, classifying them as semi-structured. Image files are raw binary streams with no inherent schema or semantic structure, therefore unstructured. This ordering correctly progresses from highest to lowest structural organization.
✗JSON documents, relational table, image filesWrong answer — click to see why▾
Why this is wrong here
JSON documents are semi-structured (schema-on-read), not more structured than a relational table with fixed columns, which is fully structured. Image files are unstructured, so the correct order is relational table (most structured), JSON documents, image files (least structured).
★ When this WOULD be the correct answer
If the question asked to order data types from least structured to most structured, then option A (JSON documents, relational table, image files) would be correct, as JSON is semi-structured, relational is structured, and images are unstructured, but reversed order.
Why candidates choose this
Candidates may mistakenly think JSON is more structured than a relational table because JSON has a defined format (key-value pairs), overlooking that relational tables enforce a rigid schema while JSON allows flexible fields.
✗Image files, relational table, JSON documentsWrong answer — click to see why▾
Why this is wrong here
Image files are unstructured, not more structured than relational tables or JSON documents. Relational tables are the most structured, followed by semi-structured JSON, then unstructured images.
★ When this WOULD be the correct answer
If the question asked to order data types from least structured to most structured, then 'image files, relational table, JSON documents' would be correct, as images are unstructured, relational tables are structured, and JSON is semi-structured.
Why candidates choose this
Candidates may mistakenly think JSON is unstructured because it lacks a fixed schema, or they may confuse the order of 'most to least' vs 'least to most' structured.
✗Relational table, image files, JSON documentsWrong answer — click to see why▾
Why this is wrong here
Image files are unstructured, not more structured than JSON documents. JSON documents have some structure (key-value pairs), while relational tables are fully structured with fixed schema.
★ When this WOULD be the correct answer
If the question asked to order data types from least to most structured, then relational table (most structured) would be last, image files (least structured) first, and JSON documents in the middle, making D correct.
Why candidates choose this
Candidates may mistakenly think that because JSON documents can have varying fields, they are less structured than image files, or they confuse 'structured' with 'complexity' or 'size'.
Analysis generated from the official DP-900blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Go deeper
Related to this question
Learn chapter
Data Roles and Core Concepts
Key term
Schema
A schema is a blueprint or logical structure that defines how data is organized, stored, and accessed in a database or information system.
Key term
Table
A table is a structured collection of data organized into rows and columns, used in databases and spreadsheets to store and manage information efficiently.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DP-900 practice question is part of Courseiva's free Microsoft 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 DP-900 exam.