WGU D426 DATA MANAGEMENT
FOUNDATIONS EXAM VERSION C
QUESTIONS AND ANSWERS
1. Which normal form is reached when a relation is in 2NF and all non-key attributes are not
transitively dependent on the primary key?
A. First Normal Form (1NF)
B. Boyce-Codd Normal Form (BCNF)
C. Third Normal Form (3NF)
D. Fourth Normal Form (4NF)
Answer: C
Conceptual Explanation: 3NF requires that the relation is in 2NF and that no non-prime
attribute is transitively dependent on any key. In other words, non-key attributes must
depend only on the primary key.
2. In the relational model, which property ensures that every row in a table is unique?
A. Entity Integrity
B. Attribute Integrity
C. Foreign Key
,D. Referential Integrity
Answer: A
Conceptual Explanation: Entity Integrity is the rule that every table must have a primary
key and that the column(s) chosen as the primary key should be unique and not null.
3. Which SQL clause is used to filter results based on the result of an aggregate function?
A. HAVING
B. GROUP BY
C. WHERE
D. ORDER BY
Answer: A
Conceptual Explanation: The HAVING clause was added to SQL because the WHERE
keyword could not be used with aggregate functions.
4. A database designer is creating a table to store monetary values. Which data type is most
appropriate to ensure precision and avoid rounding errors?
A. DECIMAL
B. REAL
C. FLOAT
D. DOUBLE
, Answer: A
Conceptual Explanation: The DECIMAL (or NUMERIC) type is an exact numeric type.
Unlike FLOAT or REAL, which are approximate, DECIMAL maintains exact precision, which
is critical for financial data.
5. Which operator is used in a WHERE clause to search for a specified pattern in a column?
A. GET
B. MATCH
C. LIKE
D. EXISTS
Answer: C
Conceptual Explanation: The LIKE operator is used along with wildcards (% for multiple
characters, _ for a single character) to perform pattern matching.
6. What is the result of the relational algebra operation ‘Projection’ (π)?
A. It returns a subset of rows from the relation.
B. It combines two relations based on a common attribute.
C. It returns a subset of columns from the relation.
D. It removes duplicate rows across two tables.
Answer: C
FOUNDATIONS EXAM VERSION C
QUESTIONS AND ANSWERS
1. Which normal form is reached when a relation is in 2NF and all non-key attributes are not
transitively dependent on the primary key?
A. First Normal Form (1NF)
B. Boyce-Codd Normal Form (BCNF)
C. Third Normal Form (3NF)
D. Fourth Normal Form (4NF)
Answer: C
Conceptual Explanation: 3NF requires that the relation is in 2NF and that no non-prime
attribute is transitively dependent on any key. In other words, non-key attributes must
depend only on the primary key.
2. In the relational model, which property ensures that every row in a table is unique?
A. Entity Integrity
B. Attribute Integrity
C. Foreign Key
,D. Referential Integrity
Answer: A
Conceptual Explanation: Entity Integrity is the rule that every table must have a primary
key and that the column(s) chosen as the primary key should be unique and not null.
3. Which SQL clause is used to filter results based on the result of an aggregate function?
A. HAVING
B. GROUP BY
C. WHERE
D. ORDER BY
Answer: A
Conceptual Explanation: The HAVING clause was added to SQL because the WHERE
keyword could not be used with aggregate functions.
4. A database designer is creating a table to store monetary values. Which data type is most
appropriate to ensure precision and avoid rounding errors?
A. DECIMAL
B. REAL
C. FLOAT
D. DOUBLE
, Answer: A
Conceptual Explanation: The DECIMAL (or NUMERIC) type is an exact numeric type.
Unlike FLOAT or REAL, which are approximate, DECIMAL maintains exact precision, which
is critical for financial data.
5. Which operator is used in a WHERE clause to search for a specified pattern in a column?
A. GET
B. MATCH
C. LIKE
D. EXISTS
Answer: C
Conceptual Explanation: The LIKE operator is used along with wildcards (% for multiple
characters, _ for a single character) to perform pattern matching.
6. What is the result of the relational algebra operation ‘Projection’ (π)?
A. It returns a subset of rows from the relation.
B. It combines two relations based on a common attribute.
C. It returns a subset of columns from the relation.
D. It removes duplicate rows across two tables.
Answer: C
