WGU D426 DATA MANAGEMENT
FOUNDATIONS - COMPREHENSIVE
EXAM STUDY GUIDE QUESTIONS AND
CORRECT DETAILED ANSWERS A+
GRADE
1. Which normal form is specifically designed to eliminate transitive dependencies?
A. Third Normal Form (3NF)
B. Second Normal Form (2NF)
C. First Normal Form (1NF)
D. Boyce-Codd Normal Form (BCNF)
Answer: A
Conceptual Explanation: Third Normal Form (3NF) requires that a table is in 2NF and
that all non-key attributes are functional only on the primary key, effectively eliminating
transitive dependencies.
2. In an Entity-Relationship Diagram (ERD), what does a dashed line for an attribute usually
signify?
A. A derived attribute
B. A primary key
,C. A multivalued attribute
D. A foreign key
Answer: A
Conceptual Explanation: Derived attributes are those whose values can be calculated
from other attributes and are typically represented by dashed lines in ERDs.
3. Which SQL clause is used to filter groups of rows after an aggregate function has been
applied?
A. HAVING
B. ORDER BY
C. LIMIT
D. WHERE
Answer: A
Conceptual Explanation: The HAVING clause is used to filter results after the GROUP BY
clause has aggregated data, whereas WHERE filters individual rows before aggregation.
4. Which property of ACID transactions ensures that once a transaction is committed, it
remains so even in the event of a system failure?
A. Atomicity
B. Consistency
C. Durability
, D. Isolation
Answer: C
Conceptual Explanation: Durability guarantees that the results of a committed
transaction are permanently recorded in the database and survive system crashes.
5. What is the primary difference between a CHAR and a VARCHAR data type in SQL?
A. CHAR is for numbers, VARCHAR is for text.
B. VARCHAR is faster for searching than CHAR.
C. CHAR is fixed-length, while VARCHAR is variable-length.
D. CHAR supports Unicode, while VARCHAR does not.
Answer: C
Conceptual Explanation: CHAR(n) allocates a fixed number of bytes regardless of the
actual string length, while VARCHAR(n) uses only the amount of space needed for the
string plus a small overhead.
6. In the context of the CAP theorem, what does the ‘P’ represent?
A. Persistence
B. Partition Tolerance
C. Performance
D. Parallelism
FOUNDATIONS - COMPREHENSIVE
EXAM STUDY GUIDE QUESTIONS AND
CORRECT DETAILED ANSWERS A+
GRADE
1. Which normal form is specifically designed to eliminate transitive dependencies?
A. Third Normal Form (3NF)
B. Second Normal Form (2NF)
C. First Normal Form (1NF)
D. Boyce-Codd Normal Form (BCNF)
Answer: A
Conceptual Explanation: Third Normal Form (3NF) requires that a table is in 2NF and
that all non-key attributes are functional only on the primary key, effectively eliminating
transitive dependencies.
2. In an Entity-Relationship Diagram (ERD), what does a dashed line for an attribute usually
signify?
A. A derived attribute
B. A primary key
,C. A multivalued attribute
D. A foreign key
Answer: A
Conceptual Explanation: Derived attributes are those whose values can be calculated
from other attributes and are typically represented by dashed lines in ERDs.
3. Which SQL clause is used to filter groups of rows after an aggregate function has been
applied?
A. HAVING
B. ORDER BY
C. LIMIT
D. WHERE
Answer: A
Conceptual Explanation: The HAVING clause is used to filter results after the GROUP BY
clause has aggregated data, whereas WHERE filters individual rows before aggregation.
4. Which property of ACID transactions ensures that once a transaction is committed, it
remains so even in the event of a system failure?
A. Atomicity
B. Consistency
C. Durability
, D. Isolation
Answer: C
Conceptual Explanation: Durability guarantees that the results of a committed
transaction are permanently recorded in the database and survive system crashes.
5. What is the primary difference between a CHAR and a VARCHAR data type in SQL?
A. CHAR is for numbers, VARCHAR is for text.
B. VARCHAR is faster for searching than CHAR.
C. CHAR is fixed-length, while VARCHAR is variable-length.
D. CHAR supports Unicode, while VARCHAR does not.
Answer: C
Conceptual Explanation: CHAR(n) allocates a fixed number of bytes regardless of the
actual string length, while VARCHAR(n) uses only the amount of space needed for the
string plus a small overhead.
6. In the context of the CAP theorem, what does the ‘P’ represent?
A. Persistence
B. Partition Tolerance
C. Performance
D. Parallelism
