WGU D426 DATA MANAGEMENT
FOUNDATIONS COMPREHENSIVE
EXAM QUESTIONS AND ANSWERS
1. Which phase of the database design process involves mapping an ER diagram to a set of
relations, ensuring all attributes are atomic and dependencies are identified?
A. Logical Design
B. Physical Design
C. Conceptual Design
D. Internal Design
Answer: A
Conceptual Explanation: Logical design transforms the conceptual model (ERD) into a
relational schema, focusing on normalization and relational structure without hardware
specifics.
2. In a relational database, what is the term for a set of one or more attributes that uniquely
identifies a tuple within a relation, but may contain extra attributes?
A. Candidate Key
B. Foreign Key
,C. Primary Key
D. Superkey
Answer: D
Conceptual Explanation: A superkey is any set of attributes that uniquely identifies a row.
A candidate key is a minimal superkey.
3. A table contains (StudentID, CourseID, Grade, CourseName). StudentID and CourseID
together form the primary key. CourseName depends only on CourseID. Which normal form
does this table violate?
A. First Normal Form (1NF)
B. Boyce-Codd Normal Form (BCNF)
C. Third Normal Form (3NF)
D. Second Normal Form (2NF)
Answer: D
Conceptual Explanation: The table violates 2NF because it contains a partial functional
dependency (CourseName depends on only part of the composite primary key).
4. Which SQL statement is used to remove all records from a table and reset the identity
seed, but retains the table structure?
A. DELETE FROM
B. DROP TABLE
, C. TRUNCATE TABLE
D. REMOVE TABLE
Answer: C
Conceptual Explanation: TRUNCATE TABLE deletes all data and resets auto-increment
values, whereas DELETE removes rows without resetting seeds and is slower.
5. Which of the following describes the ‘Atomicity’ property in the ACID model?
A. Transactions must be isolated from each other.
B. Once a transaction is committed, it stays committed even in a crash.
C. A transaction is treated as a single unit, which either succeeds completely or fails
completely.
D. Data must conform to all predefined rules and constraints.
Answer: C
Conceptual Explanation: Atomicity ensures that a transaction is ‘all or nothing.’
6. What is the primary difference between a WHERE clause and a HAVING clause in SQL?
A. WHERE is used in SELECT statements; HAVING is used in UPDATE statements.
B. HAVING is used for string comparisons, while WHERE is used for numeric comparisons.
C. WHERE filters rows before grouping; HAVING filters groups after the GROUP BY clause.
D. There is no functional difference; they are interchangeable.
FOUNDATIONS COMPREHENSIVE
EXAM QUESTIONS AND ANSWERS
1. Which phase of the database design process involves mapping an ER diagram to a set of
relations, ensuring all attributes are atomic and dependencies are identified?
A. Logical Design
B. Physical Design
C. Conceptual Design
D. Internal Design
Answer: A
Conceptual Explanation: Logical design transforms the conceptual model (ERD) into a
relational schema, focusing on normalization and relational structure without hardware
specifics.
2. In a relational database, what is the term for a set of one or more attributes that uniquely
identifies a tuple within a relation, but may contain extra attributes?
A. Candidate Key
B. Foreign Key
,C. Primary Key
D. Superkey
Answer: D
Conceptual Explanation: A superkey is any set of attributes that uniquely identifies a row.
A candidate key is a minimal superkey.
3. A table contains (StudentID, CourseID, Grade, CourseName). StudentID and CourseID
together form the primary key. CourseName depends only on CourseID. Which normal form
does this table violate?
A. First Normal Form (1NF)
B. Boyce-Codd Normal Form (BCNF)
C. Third Normal Form (3NF)
D. Second Normal Form (2NF)
Answer: D
Conceptual Explanation: The table violates 2NF because it contains a partial functional
dependency (CourseName depends on only part of the composite primary key).
4. Which SQL statement is used to remove all records from a table and reset the identity
seed, but retains the table structure?
A. DELETE FROM
B. DROP TABLE
, C. TRUNCATE TABLE
D. REMOVE TABLE
Answer: C
Conceptual Explanation: TRUNCATE TABLE deletes all data and resets auto-increment
values, whereas DELETE removes rows without resetting seeds and is slower.
5. Which of the following describes the ‘Atomicity’ property in the ACID model?
A. Transactions must be isolated from each other.
B. Once a transaction is committed, it stays committed even in a crash.
C. A transaction is treated as a single unit, which either succeeds completely or fails
completely.
D. Data must conform to all predefined rules and constraints.
Answer: C
Conceptual Explanation: Atomicity ensures that a transaction is ‘all or nothing.’
6. What is the primary difference between a WHERE clause and a HAVING clause in SQL?
A. WHERE is used in SELECT statements; HAVING is used in UPDATE statements.
B. HAVING is used for string comparisons, while WHERE is used for numeric comparisons.
C. WHERE filters rows before grouping; HAVING filters groups after the GROUP BY clause.
D. There is no functional difference; they are interchangeable.
