WGU D075 Exam 2026 – Complete Study Guide &
Practice Questions with Answers | Latest Updates
Section 1: Database & Data Management
1. What is the main purpose of a database?
A. Store data securely
B. Improve programming performance
C. Organize and manage data efficiently
D. Delete data automatically
Answer: C
Explanation: Databases are designed to organize, store, and retrieve data efficiently.
2. Which of the following is a collection of related data organized into rows and columns?
A. Tuple
B. Table
C. Key
D. Schema
Answer: B
Explanation: A table (or relation) stores records in rows and attributes in columns.
3. In an Entity-Relationship (ER) diagram, what does a diamond shape represent?
A. Entity
B. Attribute
C. Relationship
D. Key
Answer: C
Explanation: Diamonds depict the relationships between entities.
4. A foreign key is used to:
A. Store large text
B. Identify duplicates
C. Link tables together
D. Encrypt data
,Answer: C
Explanation: Foreign keys create relationships by linking a column in one table to the primary key in
another.
5. What is denormalization?
A. Making data more complex
B. Reducing the number of tables
C. Combining tables to improve performance
D. Increasing redundancy
Answer: C
Explanation: Denormalization strategically adds redundancy to a database to improve read
performance.
6. A marketing employee is tasked with mailing discount coupons to the company's top 100 customers
by sales volume. The marketing employee only has lists of customers' names, addresses, and sales
generated. Which process should this employee use?
A. Data structuring
B. Data warehousing
C. Data mining
D. Data intelligence
Answer: C
Explanation: Data mining involves analyzing data to find patterns or valuable information, such as
identifying the top customers by sales.
7. What is the key characteristic that differentiates a datamart from a data warehouse?
A. A datamart uses centralized data storage while a data warehouse is decentralized.
B. A datamart is a cloud-based service while a data warehouse requires a dedicated server.
C. A datamart is smaller and more specialized in its focus than a data warehouse.
D. A datamart allows a broader set of data structures than a data warehouse.
Answer: C
Explanation: A datamart is a subset of a data warehouse, focused on a specific business line or team.
Section 2: SQL Queries
8. Which SQL clause is used to filter rows based on a condition?
A. ORDER BY
B. GROUP BY
C. WHERE
D. SELECT
Answer: C
Explanation: The WHERE clause limits rows based on specified criteria.
, 9. What type of join returns all rows from the left table and matching rows from the right?
A. RIGHT JOIN
B. INNER JOIN
C. FULL OUTER JOIN
D. LEFT JOIN
Answer: D
Explanation: LEFT JOIN returns all records from the left table and the matched records from the right
table.
10. What function returns the number of rows in a query?
A. SUM()
B. AVG()
C. COUNT()
D. LENGTH()
Answer: C
Explanation: COUNT() is an aggregate function that counts the number of rows.
Section 3: IT Management, Hardware & Networks
11. What is the major function of a computer operating system?
A. Data management
B. Application program management
C. Network management
D. Computer resource management
Answer: D
Explanation: The OS manages hardware resources like the CPU, memory, and storage.
12. Which level of management gets the most detailed reports directly from the transaction
processing system (TPS)?
A. Supervisors
B. Managers
C. Laborers
D. Executive
Answer: A
Explanation: Supervisors and operational managers need the detailed, day-to-day data from TPS for
oversight.
13. Which type of technology can be used to monitor every product in a warehouse to enable real-
time inventory tracking and updates?
A. Wide area network (WAN)
B. Mobile utility application
Practice Questions with Answers | Latest Updates
Section 1: Database & Data Management
1. What is the main purpose of a database?
A. Store data securely
B. Improve programming performance
C. Organize and manage data efficiently
D. Delete data automatically
Answer: C
Explanation: Databases are designed to organize, store, and retrieve data efficiently.
2. Which of the following is a collection of related data organized into rows and columns?
A. Tuple
B. Table
C. Key
D. Schema
Answer: B
Explanation: A table (or relation) stores records in rows and attributes in columns.
3. In an Entity-Relationship (ER) diagram, what does a diamond shape represent?
A. Entity
B. Attribute
C. Relationship
D. Key
Answer: C
Explanation: Diamonds depict the relationships between entities.
4. A foreign key is used to:
A. Store large text
B. Identify duplicates
C. Link tables together
D. Encrypt data
,Answer: C
Explanation: Foreign keys create relationships by linking a column in one table to the primary key in
another.
5. What is denormalization?
A. Making data more complex
B. Reducing the number of tables
C. Combining tables to improve performance
D. Increasing redundancy
Answer: C
Explanation: Denormalization strategically adds redundancy to a database to improve read
performance.
6. A marketing employee is tasked with mailing discount coupons to the company's top 100 customers
by sales volume. The marketing employee only has lists of customers' names, addresses, and sales
generated. Which process should this employee use?
A. Data structuring
B. Data warehousing
C. Data mining
D. Data intelligence
Answer: C
Explanation: Data mining involves analyzing data to find patterns or valuable information, such as
identifying the top customers by sales.
7. What is the key characteristic that differentiates a datamart from a data warehouse?
A. A datamart uses centralized data storage while a data warehouse is decentralized.
B. A datamart is a cloud-based service while a data warehouse requires a dedicated server.
C. A datamart is smaller and more specialized in its focus than a data warehouse.
D. A datamart allows a broader set of data structures than a data warehouse.
Answer: C
Explanation: A datamart is a subset of a data warehouse, focused on a specific business line or team.
Section 2: SQL Queries
8. Which SQL clause is used to filter rows based on a condition?
A. ORDER BY
B. GROUP BY
C. WHERE
D. SELECT
Answer: C
Explanation: The WHERE clause limits rows based on specified criteria.
, 9. What type of join returns all rows from the left table and matching rows from the right?
A. RIGHT JOIN
B. INNER JOIN
C. FULL OUTER JOIN
D. LEFT JOIN
Answer: D
Explanation: LEFT JOIN returns all records from the left table and the matched records from the right
table.
10. What function returns the number of rows in a query?
A. SUM()
B. AVG()
C. COUNT()
D. LENGTH()
Answer: C
Explanation: COUNT() is an aggregate function that counts the number of rows.
Section 3: IT Management, Hardware & Networks
11. What is the major function of a computer operating system?
A. Data management
B. Application program management
C. Network management
D. Computer resource management
Answer: D
Explanation: The OS manages hardware resources like the CPU, memory, and storage.
12. Which level of management gets the most detailed reports directly from the transaction
processing system (TPS)?
A. Supervisors
B. Managers
C. Laborers
D. Executive
Answer: A
Explanation: Supervisors and operational managers need the detailed, day-to-day data from TPS for
oversight.
13. Which type of technology can be used to monitor every product in a warehouse to enable real-
time inventory tracking and updates?
A. Wide area network (WAN)
B. Mobile utility application
