WGU D427 DATA MANAGEMENT
APPLICATIONS OA FINAL PREP
QUESTIONS AND ANSWERS
1. Which normal form requires that all non-key attributes are fully functionally dependent on
the entire primary key, eliminating partial dependencies?
A. First Normal Form (1NF)
B. Third Normal Form (3NF)
C. Second Normal Form (2NF)
D. Boyce-Codd Normal Form (BCNF)
Answer: C
Conceptual Explanation: Second Normal Form (2NF) addresses partial dependencies,
meaning no non-prime attribute is dependent on a subset of any candidate key.
2. Which SQL keyword is used to filter results from a query that includes an aggregate
function, such as SUM or COUNT?
A. WHERE
B. ORDER BY
,C. HAVING
D. GROUP BY
Answer: C
Conceptual Explanation: The HAVING clause is used specifically to filter groups created
by the GROUP BY clause based on aggregate values.
3. In a relational database, what is the term for a column or group of columns that uniquely
identifies a row in another table?
A. Primary Key
B. Composite Key
C. Foreign Key
D. Candidate Key
Answer: C
Conceptual Explanation: A Foreign Key is an attribute in one table that provides a link to
the Primary Key of another table.
4. Which command is used to remove all records from a table and reset the auto-increment
counter, but keep the table structure intact?
A. DELETE
B. TRUNCATE
C. DROP
, D. REMOVE
Answer: B
Conceptual Explanation: TRUNCATE is a DDL command that deletes all rows in a table
faster than DELETE and resets identity seeds.
5. Which data type is most appropriate for a column storing prices that require high precision
and no rounding errors?
A. FLOAT
B. DOUBLE
C. DECIMAL
D. INTEGER
Answer: C
Conceptual Explanation: DECIMAL (or NUMERIC) is an exact data type used for financial
data where precision is critical.
6. What occurs when a non-key attribute depends on another non-key attribute rather than
the primary key?
A. Partial Dependency
B. Transitive Dependency
C. Functional Dependency
D. Multi-valued Dependency
APPLICATIONS OA FINAL PREP
QUESTIONS AND ANSWERS
1. Which normal form requires that all non-key attributes are fully functionally dependent on
the entire primary key, eliminating partial dependencies?
A. First Normal Form (1NF)
B. Third Normal Form (3NF)
C. Second Normal Form (2NF)
D. Boyce-Codd Normal Form (BCNF)
Answer: C
Conceptual Explanation: Second Normal Form (2NF) addresses partial dependencies,
meaning no non-prime attribute is dependent on a subset of any candidate key.
2. Which SQL keyword is used to filter results from a query that includes an aggregate
function, such as SUM or COUNT?
A. WHERE
B. ORDER BY
,C. HAVING
D. GROUP BY
Answer: C
Conceptual Explanation: The HAVING clause is used specifically to filter groups created
by the GROUP BY clause based on aggregate values.
3. In a relational database, what is the term for a column or group of columns that uniquely
identifies a row in another table?
A. Primary Key
B. Composite Key
C. Foreign Key
D. Candidate Key
Answer: C
Conceptual Explanation: A Foreign Key is an attribute in one table that provides a link to
the Primary Key of another table.
4. Which command is used to remove all records from a table and reset the auto-increment
counter, but keep the table structure intact?
A. DELETE
B. TRUNCATE
C. DROP
, D. REMOVE
Answer: B
Conceptual Explanation: TRUNCATE is a DDL command that deletes all rows in a table
faster than DELETE and resets identity seeds.
5. Which data type is most appropriate for a column storing prices that require high precision
and no rounding errors?
A. FLOAT
B. DOUBLE
C. DECIMAL
D. INTEGER
Answer: C
Conceptual Explanation: DECIMAL (or NUMERIC) is an exact data type used for financial
data where precision is critical.
6. What occurs when a non-key attribute depends on another non-key attribute rather than
the primary key?
A. Partial Dependency
B. Transitive Dependency
C. Functional Dependency
D. Multi-valued Dependency
