WGU D426 Data Management
Foundations OA Exam
Questions And Correct
Answers (Verified Answers)
Plus Rationales 2025/2026
Q&A | Instant Download Pdf
1. What is the primary purpose of a database?
A. To store programs
B. To store and manage structured data
C. To compile code
D. To design networks
Answer: B. To store and manage structured data
Rationale: A database is designed to efficiently store,
retrieve, and manage structured data.
2. What does SQL stand for?
A. Structured Query Language
B. Standard Question Language
C. Simple Query List
D. Sequential Query Logic
,Answer: A. Structured Query Language
Rationale: SQL is the standard language used to interact
with relational databases.
3. Which of the following is a primary key?
A. A duplicate column
B. A column that uniquely identifies each row
C. A foreign table
D. A computed field
Answer: B. A column that uniquely identifies each row
Rationale: A primary key must be unique and cannot
contain NULL values.
4. What is a foreign key?
A. A key used only in Excel
B. A key that uniquely identifies a table
C. A field that links two tables together
D. A password field
Answer: C. A field that links two tables together
Rationale: A foreign key establishes relationships between
tables.
5. Which normal form removes repeating groups?
A. 1NF
B. 2NF
,C. 3NF
D. BCNF
Answer: A. 1NF
Rationale: First Normal Form eliminates repeating groups
and ensures atomic values.
6. What is denormalization?
A. Breaking tables into smaller tables
B. Removing all keys
C. Combining tables for performance optimization
D. Encrypting data
Answer: C. Combining tables for performance optimization
Rationale: Denormalization introduces redundancy to
improve query performance.
7. Which SQL command retrieves data?
A. INSERT
B. UPDATE
C. SELECT
D. DELETE
Answer: C. SELECT
Rationale: SELECT is used to query and retrieve data from a
database.
8. What is an ERD used for?
, A. Encrypting data
B. Designing database structure
C. Running queries
D. Backing up data
Answer: B. Designing database structure
Rationale: Entity-Relationship Diagrams model data
relationships.
9. What does ACID stand for in databases?
A. Access, Control, Input, Data
B. Atomicity, Consistency, Isolation, Durability
C. Action, Commit, Index, Data
D. Automation, Connection, Integrity, Design
Answer: B. Atomicity, Consistency, Isolation, Durability
Rationale: ACID ensures reliable database transactions.
10. Which constraint ensures no NULL values?
A. UNIQUE
B. NOT NULL
C. PRIMARY KEY
D. CHECK
Answer: B. NOT NULL
Rationale: NOT NULL ensures a column must always contain
a value.
Foundations OA Exam
Questions And Correct
Answers (Verified Answers)
Plus Rationales 2025/2026
Q&A | Instant Download Pdf
1. What is the primary purpose of a database?
A. To store programs
B. To store and manage structured data
C. To compile code
D. To design networks
Answer: B. To store and manage structured data
Rationale: A database is designed to efficiently store,
retrieve, and manage structured data.
2. What does SQL stand for?
A. Structured Query Language
B. Standard Question Language
C. Simple Query List
D. Sequential Query Logic
,Answer: A. Structured Query Language
Rationale: SQL is the standard language used to interact
with relational databases.
3. Which of the following is a primary key?
A. A duplicate column
B. A column that uniquely identifies each row
C. A foreign table
D. A computed field
Answer: B. A column that uniquely identifies each row
Rationale: A primary key must be unique and cannot
contain NULL values.
4. What is a foreign key?
A. A key used only in Excel
B. A key that uniquely identifies a table
C. A field that links two tables together
D. A password field
Answer: C. A field that links two tables together
Rationale: A foreign key establishes relationships between
tables.
5. Which normal form removes repeating groups?
A. 1NF
B. 2NF
,C. 3NF
D. BCNF
Answer: A. 1NF
Rationale: First Normal Form eliminates repeating groups
and ensures atomic values.
6. What is denormalization?
A. Breaking tables into smaller tables
B. Removing all keys
C. Combining tables for performance optimization
D. Encrypting data
Answer: C. Combining tables for performance optimization
Rationale: Denormalization introduces redundancy to
improve query performance.
7. Which SQL command retrieves data?
A. INSERT
B. UPDATE
C. SELECT
D. DELETE
Answer: C. SELECT
Rationale: SELECT is used to query and retrieve data from a
database.
8. What is an ERD used for?
, A. Encrypting data
B. Designing database structure
C. Running queries
D. Backing up data
Answer: B. Designing database structure
Rationale: Entity-Relationship Diagrams model data
relationships.
9. What does ACID stand for in databases?
A. Access, Control, Input, Data
B. Atomicity, Consistency, Isolation, Durability
C. Action, Commit, Index, Data
D. Automation, Connection, Integrity, Design
Answer: B. Atomicity, Consistency, Isolation, Durability
Rationale: ACID ensures reliable database transactions.
10. Which constraint ensures no NULL values?
A. UNIQUE
B. NOT NULL
C. PRIMARY KEY
D. CHECK
Answer: B. NOT NULL
Rationale: NOT NULL ensures a column must always contain
a value.
