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WorksheetsDBMS Unit 4
Total questions: 15
Worksheet time: 8mins
You’re managing a company database. You find yourself updating the same department name in multiple rows. What pitfall are you facing?
Complexity
Redundancy
Inconsistency
Partial Dependency
A user updates their address, but only half the records reflect the change. What anomaly has crept in?
Insertion anomaly
Update anomaly
Join dependency
Reflexivity trap
Your table tracks students and the courses they take, but every new course entry requires duplicating the student's info. What should you normalize to avoid?
Data minimalism
Foreign key overload
Redundancy
Deletion anomaly
Q4. Two departments offer the same salary, but due to inconsistent updates, salaries now differ. What went wrong?
A) Lack of multivalued dependency
B) Transitive error
C) Functional dependency failure
D) Inconsistency
Q5. In your pizza order system, customer name depends on order ID, and topping depends on pizza ID. Combining all in one table leads to?
A) Join anomaly
B) Lossless decomposition
C) Repetition party
D) Design inefficiency
What is a major drawback of data redundancy in a relational database?
Increased performance
Reduced query complexity
Inconsistent data versions
Improved data availability
Which of the following best defines a functional dependency (FD)?
A rule that allows repeating groups
A relation where data is stored redundantly
A constraint where one attribute determines another
A rule for ensuring lossless decomposition
What is a trivial functional dependency?
A FD that is always false
A FD where the right side is a subset of the left
A FD with no primary key
A FD that causes anomalies
What is the goal of normalization in relational database design?
Increase redundancy
Improve indexing
Eliminate anomalies and redundancy
Add more attributes
Which of the following is not an anomaly addressed by normalization?
Selection Anomaly
Insertion Anomaly
Deletion Anomaly
Update Anomaly
In which normal form are all values atomic and no repeating groups allowed?
2NF
3NF
1NF
BCNF
What is partial dependency, and which normal form removes it?
FD based on only part of a candidate key; removed in 2NF
FD involving primary key only; removed in 1NF
FD involving foreign keys; removed in 3NF
FD with multiple keys; removed in BCNF
What is transitive dependency, and which NF removes it?
A → B and B → C implies A → C; removed in 3NF
A → A; removed in 1NF
A →→ B; removed in 4NF
A ⋈ B = R; removed in 5NF
What makes a schema satisfy Boyce-Codd Normal Form (BCNF)?
All attributes are atomic
No non-prime attribute is transitively dependent
Every determinant is a candidate key
No multivalued dependency exists
Which of the following is true about 4NF?
It eliminates transitive dependencies
It removes join dependencies
It removes multi-valued dependencies
It ensures atomic values
