D426 DATA MANAGEMENT
FOUNDATIONS - EXAM PREP
QUESTIONS AND ANSWERS
1. Which normal form is specifically violated when a non-prime attribute is functionally
dependent on a part of a composite primary key?
A. Second Normal Form (2NF)
B. First Normal Form (1NF)
C. Third Normal Form (3NF)
D. Boyce-Codd Normal Form (BCNF)
Answer: A
Conceptual Explanation: Second Normal Form (2NF) requires that all non-prime
attributes are fully functionally dependent on the entire primary key. A dependency on a
part of a composite key is a partial dependency, violating 2NF.
2. In the context of the Relational Model, what does the ‘Selection’ (sigma) operator in
relational algebra achieve?
A. It extracts specific columns from a relation.
,B. It filters rows that satisfy a specific predicate.
C. It combines rows from two different tables.
D. It removes duplicate rows from the result set.
Answer: B
Conceptual Explanation: The Selection operator (represented by sigma) filters the
horizontal subsets (rows) of a relation based on a specified condition.
3. Which SQL clause is used to filter groups of rows after an aggregate function has been
applied?
A. HAVING
B. ORDER BY
C. GROUP BY
D. WHERE
Answer: A
Conceptual Explanation: The HAVING clause is used to filter groups created by the
GROUP BY clause based on aggregate results. WHERE filters individual rows before
grouping.
4. A database designer uses a surrogate key in a table. What is the primary reason for this
decision?
A. To enforce a natural relationship between tables.
, B. To ensure that the table is in First Normal Form.
C. To improve the readability of the data for end-users.
D. To provide a unique, system-generated identifier when no natural key is suitable.
Answer: D
Conceptual Explanation: Surrogate keys are artificial identifiers (often integers) used as
primary keys when natural keys are complex, non-unique, or non-existent.
5. Which property of the ACID model ensures that a transaction is treated as a single unit,
which either succeeds entirely or fails entirely?
A. Atomicity
B. Isolation
C. Consistency
D. Durability
Answer: A
Conceptual Explanation: Atomicity ensures that all operations within a transaction are
completed; if any part fails, the entire transaction is rolled back.
6. What is the result of a SQL ‘CROSS JOIN’ between Table A with 10 rows and Table B with 5
rows?
A. A table with 50 rows.
B. A table with 15 rows.
FOUNDATIONS - EXAM PREP
QUESTIONS AND ANSWERS
1. Which normal form is specifically violated when a non-prime attribute is functionally
dependent on a part of a composite primary key?
A. Second Normal Form (2NF)
B. First Normal Form (1NF)
C. Third Normal Form (3NF)
D. Boyce-Codd Normal Form (BCNF)
Answer: A
Conceptual Explanation: Second Normal Form (2NF) requires that all non-prime
attributes are fully functionally dependent on the entire primary key. A dependency on a
part of a composite key is a partial dependency, violating 2NF.
2. In the context of the Relational Model, what does the ‘Selection’ (sigma) operator in
relational algebra achieve?
A. It extracts specific columns from a relation.
,B. It filters rows that satisfy a specific predicate.
C. It combines rows from two different tables.
D. It removes duplicate rows from the result set.
Answer: B
Conceptual Explanation: The Selection operator (represented by sigma) filters the
horizontal subsets (rows) of a relation based on a specified condition.
3. Which SQL clause is used to filter groups of rows after an aggregate function has been
applied?
A. HAVING
B. ORDER BY
C. GROUP BY
D. WHERE
Answer: A
Conceptual Explanation: The HAVING clause is used to filter groups created by the
GROUP BY clause based on aggregate results. WHERE filters individual rows before
grouping.
4. A database designer uses a surrogate key in a table. What is the primary reason for this
decision?
A. To enforce a natural relationship between tables.
, B. To ensure that the table is in First Normal Form.
C. To improve the readability of the data for end-users.
D. To provide a unique, system-generated identifier when no natural key is suitable.
Answer: D
Conceptual Explanation: Surrogate keys are artificial identifiers (often integers) used as
primary keys when natural keys are complex, non-unique, or non-existent.
5. Which property of the ACID model ensures that a transaction is treated as a single unit,
which either succeeds entirely or fails entirely?
A. Atomicity
B. Isolation
C. Consistency
D. Durability
Answer: A
Conceptual Explanation: Atomicity ensures that all operations within a transaction are
completed; if any part fails, the entire transaction is rolled back.
6. What is the result of a SQL ‘CROSS JOIN’ between Table A with 10 rows and Table B with 5
rows?
A. A table with 50 rows.
B. A table with 15 rows.
