D426 DATA MANAGEMENT
FOUNDATIONS - COMPREHENSIVE
PREP EXAM QUESTIONS AND
ANSWERS
1. Which of the following describes a set of attributes in a relation that uniquely identifies a
tuple, but from which no attribute can be removed without losing the uniqueness property?
A. Candidate Key
B. Super Key
C. Foreign Key
D. Secondary Key
Answer: A
Conceptual Explanation: A candidate key is a minimal super key. While a super key
uniquely identifies a tuple, a candidate key is the smallest possible set of attributes that
maintains uniqueness.
,2. In the context of database normalization, which normal form specifically addresses the
removal of transitive dependencies?
A. First Normal Form (1NF)
B. Second Normal Form (2NF)
C. Third Normal Form (3NF)
D. Boyce-Codd Normal Form (BCNF)
Answer: C
Conceptual Explanation: Third Normal Form (3NF) requires that the table is in 2NF and
that all non-key attributes are functionally dependent only on the primary key, effectively
removing transitive dependencies.
3. Which SQL statement category is used to define, modify, or delete the structure of
database objects such as tables and indexes?
A. DDL (Data Definition Language)
B. DQL (Data Query Language)
C. DML (Data Manipulation Language)
D. DCL (Data Control Language)
Answer: A
Conceptual Explanation: DDL (Data Definition Language) includes commands like
CREATE, ALTER, and DROP, which define the schema and structure of the database.
, 4. What is the primary difference between a ‘DELETE’ statement and a ‘TRUNCATE’ statement
in SQL?
A. DELETE removes the table structure, while TRUNCATE only removes data.
B. TRUNCATE is slower than DELETE for large datasets.
C. DELETE cannot be used with a WHERE clause, while TRUNCATE can.
D. TRUNCATE is a DDL operation that resets identity columns, while DELETE is DML and
removes rows one by one.
Answer: D
Conceptual Explanation: TRUNCATE is a DDL command that deallocates data pages and
resets auto-incrementing counters, making it faster but less granular than the DML DELETE
command.
5. Which property of the ACID model ensures that a transaction is treated as a single unit,
which either succeeds completely or fails completely?
A. Durability
B. Consistency
C. Isolation
D. Atomicity
Answer: D
FOUNDATIONS - COMPREHENSIVE
PREP EXAM QUESTIONS AND
ANSWERS
1. Which of the following describes a set of attributes in a relation that uniquely identifies a
tuple, but from which no attribute can be removed without losing the uniqueness property?
A. Candidate Key
B. Super Key
C. Foreign Key
D. Secondary Key
Answer: A
Conceptual Explanation: A candidate key is a minimal super key. While a super key
uniquely identifies a tuple, a candidate key is the smallest possible set of attributes that
maintains uniqueness.
,2. In the context of database normalization, which normal form specifically addresses the
removal of transitive dependencies?
A. First Normal Form (1NF)
B. Second Normal Form (2NF)
C. Third Normal Form (3NF)
D. Boyce-Codd Normal Form (BCNF)
Answer: C
Conceptual Explanation: Third Normal Form (3NF) requires that the table is in 2NF and
that all non-key attributes are functionally dependent only on the primary key, effectively
removing transitive dependencies.
3. Which SQL statement category is used to define, modify, or delete the structure of
database objects such as tables and indexes?
A. DDL (Data Definition Language)
B. DQL (Data Query Language)
C. DML (Data Manipulation Language)
D. DCL (Data Control Language)
Answer: A
Conceptual Explanation: DDL (Data Definition Language) includes commands like
CREATE, ALTER, and DROP, which define the schema and structure of the database.
, 4. What is the primary difference between a ‘DELETE’ statement and a ‘TRUNCATE’ statement
in SQL?
A. DELETE removes the table structure, while TRUNCATE only removes data.
B. TRUNCATE is slower than DELETE for large datasets.
C. DELETE cannot be used with a WHERE clause, while TRUNCATE can.
D. TRUNCATE is a DDL operation that resets identity columns, while DELETE is DML and
removes rows one by one.
Answer: D
Conceptual Explanation: TRUNCATE is a DDL command that deallocates data pages and
resets auto-incrementing counters, making it faster but less granular than the DML DELETE
command.
5. Which property of the ACID model ensures that a transaction is treated as a single unit,
which either succeeds completely or fails completely?
A. Durability
B. Consistency
C. Isolation
D. Atomicity
Answer: D
