1. In the context of entity-relationship (ER) modeling, an entity is represented by:
A. A rectangle.
B. An oval.
C. A diamond.
D. A hexagon.
Answer: A
Rationale: In ER modeling, entities are represented by rectangles, which symbolize
the objects or things in the real world that are of interest to the database.
2. What is the main purpose of data abstraction in database systems?
A. To hide unnecessary details and show only essential features.
B. To make databases more complex.
C. To optimize query execution.
D. To enforce data integrity.
Answer: A
,Rationale: Data abstraction helps simplify database interactions by hiding
unnecessary details and showing only the necessary data to users and applications.
3. Which of the following is a logical model in database design?
A. Relational model
B. Physical model
C. Columnar model
D. File system model
Answer: A
Rationale: The relational model is a logical model in database design, where data is
stored in tables and manipulated using SQL.
4. Which normal form eliminates 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
, Rationale: The third normal form (3NF) eliminates transitive dependencies, which
occur when a non-key attribute depends on another non-key attribute.
5. Normalization involves:
A. Reducing data redundancy by organizing data into multiple tables.
B. Removing tables from the database to save space.
C. Adding more indexes to speed up queries.
D. Changing the storage format of data.
Answer: A
Rationale: Normalization reduces data redundancy by organizing data into smaller
tables based on functional dependencies and removing anomalies.
6. What is an index used for in a database?
A. To store large amounts of data.
B. To increase query performance by allowing faster lookups.
C. To ensure referential integrity.
D. To group data together for backup purposes.
Answer: B
A. A rectangle.
B. An oval.
C. A diamond.
D. A hexagon.
Answer: A
Rationale: In ER modeling, entities are represented by rectangles, which symbolize
the objects or things in the real world that are of interest to the database.
2. What is the main purpose of data abstraction in database systems?
A. To hide unnecessary details and show only essential features.
B. To make databases more complex.
C. To optimize query execution.
D. To enforce data integrity.
Answer: A
,Rationale: Data abstraction helps simplify database interactions by hiding
unnecessary details and showing only the necessary data to users and applications.
3. Which of the following is a logical model in database design?
A. Relational model
B. Physical model
C. Columnar model
D. File system model
Answer: A
Rationale: The relational model is a logical model in database design, where data is
stored in tables and manipulated using SQL.
4. Which normal form eliminates 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
, Rationale: The third normal form (3NF) eliminates transitive dependencies, which
occur when a non-key attribute depends on another non-key attribute.
5. Normalization involves:
A. Reducing data redundancy by organizing data into multiple tables.
B. Removing tables from the database to save space.
C. Adding more indexes to speed up queries.
D. Changing the storage format of data.
Answer: A
Rationale: Normalization reduces data redundancy by organizing data into smaller
tables based on functional dependencies and removing anomalies.
6. What is an index used for in a database?
A. To store large amounts of data.
B. To increase query performance by allowing faster lookups.
C. To ensure referential integrity.
D. To group data together for backup purposes.
Answer: B
