Washington Data Engineering Professional Certification Exam Prep: Questions, Answers, and Detailed Rationales

Washington Data Engineering Professional
Course Questions And Correct Answer with
Rational (100% verified answer) Q & A 2026
/Instant download PDF
1. What is the primary purpose of data engineering?
A. Designing mobile apps
B. Building and maintaining data pipelines
C. Creating animations
D. Repairing hardware
Rationale: Data engineering focuses on building systems and pipelines that collect,
process, and store data efficiently.
2. Which database type stores data in rows and tables?
A. NoSQL
B. Graph Database
C. Relational Database
D. Key-Value Store
Rationale: Relational databases organize data into structured tables with rows
and columns.
3. Which language is widely used in data engineering?
A. HTML
B. CSS
C. Python
D. Photoshop
Rationale: Python is commonly used for automation, ETL, and big data processing.
4. What does ETL stand for?
A. Extract, Transform, Load
B. Enter, Transfer, Link

, C. Export, Translate, Load
D. Evaluate, Test, Launch
Rationale: ETL refers to extracting data, transforming it, and loading it into a
target system.
5. Which tool is commonly used for big data processing?
A. Apache Spark
B. Canva
C. Blender
D. Photoshop
Rationale: Apache Spark is a powerful distributed data processing framework.
6. What is a data pipeline?
A. A plumbing system
B. A sequence of data processing steps
C. A gaming framework
D. A hardware cable
Rationale: Data pipelines automate the movement and transformation of data.
7. Which SQL command retrieves data?
A. UPDATE
B. INSERT
C. SELECT
D. DELETE
Rationale: SELECT is used to query and retrieve records from databases.
8. What is the purpose of a primary key?
A. Encrypt records
B. Identify unique rows
C. Delete duplicates
D. Compress data
Rationale: A primary key uniquely identifies each record in a table.

, 9. Which cloud platform offers data engineering services?
A. AWS
B. Netflix
C. Spotify
D. TikTok
Rationale: AWS provides cloud-based storage, analytics, and processing services.
10.What is data normalization?
A. Backing up files
B. Organizing data to reduce redundancy
C. Increasing image size
D. Encrypting databases
Rationale: Normalization minimizes duplicate data and improves database
efficiency.
11.Which file format is commonly used for big data storage?
A. MP3
B. JPEG
C. Parquet
D. AVI
Rationale: Parquet is a columnar storage format optimized for analytics.
12.What does SQL stand for?
A. Structured Query Language
B. Standard Queue Logic
C. System Query Link
D. Secure Question Layer
Rationale: SQL is the standard language for managing relational databases.
13.Which database is a NoSQL database?
A. PostgreSQL
B. Oracle