DP-900 Describe core data concepts Practice Question
A company stores an employee database in a relational database. The Employees table includes columns: EmployeeID (integer), FirstName (text), LastName (text), HireDate (date), and a column called Photo which stores the employee's photo as a binary large object (BLOB). Which statement best describes the data types in this table?
⚠ Common exam trap
It's easy for candidates to assume all columns in a relational database are structured, overlooking that BLOB columns store unstructured binary data, which is a key distinction tested in the DP-900 exam under core data concepts.
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
✓
The Photo column stores unstructured data, while the other columns store structured data.
The Photo column stores a binary large object (BLOB), which is unstructured data because it does not have a predefined schema or format that can be easily queried or indexed by relational operations. In contrast, EmployeeID, FirstName, LastName, and HireDate are all structured data types (integer, text, date) that conform to a fixed schema and support direct querying, sorting, and indexing. This distinction is fundamental in Azure data services, where structured data is typically stored in Azure SQL Database or Azure Synapse, while unstructured BLOBs are better suited for Azure Blob Storage.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
All columns store structured data.
Why it's wrong here
This claim is incorrect because the table includes a Photo column that stores binary image data. In a relational database, most columns (EmployeeID, FirstName, LastName, HireDate) conform to a defined schema with explicit data types such as INT, VARCHAR, and DATE, which makes them structured. However, the Photo column holds a BLOB (binary large object) with no inherent schema, keys, or semantic structure; its contents are images, which are classic unstructured data. Thus, stating that all columns store structured data ignores the one column that does not fit the fixed schema.
- ✓
The Photo column stores unstructured data, while the other columns store structured data.
Why this is correct
Structured data is organized with a fixed schema; the integer, text, and date columns all have a fixed type and format. The Photo column contains binary image data with no inherent structure, making it unstructured data.
- ✗
All columns store unstructured data.
Why it's wrong here
This claim is incorrect because the vast majority of columns in the employee table are strongly typed and follow a rigid, pre-defined schema. EmployeeID is an integer, FirstName and LastName are text strings, and HireDate is a date type — each has a fixed format and atomic value, which is the definition of structured data. The Photo column, storing raw binary image data, is the only unstructured column; labeling the entire table as unstructured conflates the nature of one column with the rest. Even though the table itself is a structured object, the data in most columns is organized into well-defined fields, not free-form or untyped.
- ✗
The HireDate column stores semi-structured data.
Why it's wrong here
This claim is incorrect because HireDate is a relational column with a fixed DATE data type, not a semi-structured format. Semi-structured data is characterized by self-describing tags or markers (for example, JSON objects or XML elements) that carry schema information alongside the values. In contrast, HireDate has a strict, predefined format and occupies a fixed column in the table's schema; it is fully structured. The presence of a date with a specific year, month, and day does not make it semi-structured, as it lacks the hierarchical or nested structure typical of JSON or XML.
Quick reference
Azure Blob Storage Tier Comparison
| Tier | Storage Cost | Retrieval Cost | Latency | Use Case |
|---|---|---|---|---|
| Hot | Highest | Lowest | Immediate | Active data, frequent reads |
| Cool | Lower | Higher | Immediate | Data accessed < once / month |
| Cold | Lower still | Higher | Immediate | Data accessed < once / quarter |
| Archive | Lowest | Highest + rehydration delay | Hours | Long-term compliance retention |
Go deeper
Related to this question
Learn chapter
Data Roles and Core Concepts
Key term
Data
Data is raw, unprocessed information, like numbers, words, or measurements, that can be stored, processed, and analyzed by computers.
Key term
Azure SQL Database
Azure SQL Database is a fully managed relational database-as-a-service (DBaaS) in Microsoft Azure, based on the SQL Server engine, that handles scaling, backups, patching, and high availability automatically.
About these practice questions
One of 820 original DP-900 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 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.