Database Normalization: Master the Basics for Efficient Data Management

Question 1

Identify the key distinction between Boyce-Codd Normal Form (BCNF) and 3NF. Explain why BCNF is considered a stricter normalization level.

Accepted Answer

BCNF mandates that every non-key attribute be solely dependent on the primary key, while 3NF permits non-key attributes to depend on candidate keys.

Answer

BCNF is a less stringent normalization level than 3NF, allowing partial dependencies.

Answer

BCNF and 3NF are equivalent normalization levels, offering the same level of data integrity.

Answer

BCNF applies only to tables with a single primary key, whereas 3NF can be applied to tables with multiple primary keys.

Question 2

Which of the following requirements must be met for a database table to be in First Normal Form (1NF)?

Accepted Answer

No repeating groups of values within a row

Answer

No partial dependencies on the primary key

Answer

No transitive dependencies on the primary key

Answer

All attributes must be atomic (indivisible)

Question 3

A relation is in Second Normal Form (2NF) if it is in 1NF and also satisfies which condition?

Accepted Answer

Every non-prime attribute is fully dependent on the primary key.

Answer

Every non-prime attribute is partially dependent on the primary key.

Answer

Every non-prime attribute is transitively dependent on the primary key.

Answer

It satisfies the Boyce-Codd Normal Form (BCNF).

Question 4

Which of the following is NOT a potential benefit of database normalization?

Accepted Answer

Increased data retrieval speed in all cases

Answer

Improved data integrity

Answer

Reduced data redundancy

Answer

Simplified database design

Question 5

A relation is in BCNF if and only if it is in:

Accepted Answer

1NF, 2NF, and 3NF

Answer

1NF and 2NF

Answer

2NF and 3NF

Answer

3NF and 4NF

Question 6

Which of the following factors should NOT be considered when choosing an appropriate normal form for a database?

Accepted Answer

User experience

Answer

Type and complexity of queries

Answer

Volume of data

Answer

Hardware and software capabilities

Question 7

Which normal form prohibits transitive functional dependencies?

Accepted Answer

BCNF

Answer

1NF

Answer

2NF

Answer

3NF

Question 8

Which of the following is the most common technique used to achieve BCNF?

Accepted Answer

Decomposition

Answer

Data duplication

Answer

Referential integrity constraints

Answer

Denormalization

Question 9

Which of the following is a property of a database in 2NF?

Accepted Answer

Each non-prime attribute is dependent only on the primary key.

Answer

Tables are normalized to 1NF.

Answer

Every attribute is functionally dependent on every other attribute.

Answer

Tables are free from repeating groups.

Question 10

Which normal form addresses the issue of transitive dependencies?

Accepted Answer

BCNF

Answer

1NF

Answer

2NF

Answer

3NF

Question 11

What is the definition of Boyce-Codd normal form (BCNF)?

Accepted Answer

Every determinant is a candidate key.

Answer

Transitive dependencies are eliminated.

Answer

Data integrity is guaranteed.

Answer

3NF is always achieved first.

Question 12

Which of the following is NOT a decomposition technique used in database normalization?

Accepted Answer

Join dependency analysis.

Answer

Functional dependency analysis.

Answer

Multi-valued dependency analysis.

Answer

Candidate key analysis.

Question 13

How do candidate keys and primary keys differ?

Accepted Answer

A candidate key is a minimal set of attributes that uniquely identifies a row, while a primary key is a candidate key chosen as the unique identifier.

Answer

A primary key is a minimal set of attributes that uniquely identifies a row, while a candidate key includes the primary key.

Answer

There is no difference between a candidate key and a primary key.

Answer

A candidate key is a unique identifier for a table, while a primary key is a unique identifier for a row.

Question 14

Under which circumstance could denormalizing a database be a reasonable choice?

Accepted Answer

When optimizing query performance is a priority

Accepted Answer

When simplifying data retrieval is a key consideration

Answer

When enhancing data integrity is the primary objective

Answer

When minimizing data storage space is a top priority

Question 15

In database normalization, what is a functional dependency?

Accepted Answer

One attribute (determinant) uniquely determines the value of another attribute (dependent).

Answer

A rule that ensures data consistency and adherence to specific constraints.

Answer

A definition of the table's primary key, ensuring unique row identification.

Answer

A condition that prevents duplicate row insertion, maintaining data integrity.

Question 16

When designing a database, how should the benefits of normalization be balanced against factors like performance and usability?

Accepted Answer

The optimal balance between normalization, performance, and usability depends on the specific needs of the database.

Answer

Normalization should always be prioritized over performance and usability.

Answer

Performance and usability should always be prioritized over normalization.

Answer

Performance and usability are irrelevant when designing a normalized database.

Question 17

The primary objective of database normalization is to:

Accepted Answer

Eliminate data redundancy

Answer

Ensure data consistency

Answer

Enhance data accessibility

Answer

Optimize storage efficiency

Question 18

In first normal form (1NF), each column in a relation must contain:

Accepted Answer

Indivisible values

Answer

A unique column name

Answer

A primary key

Answer

A foreign key

Question 19

The process of dividing a relation into multiple smaller relations while preserving the original data is called:

Accepted Answer

Normalization

Answer

Denormalization

Answer

Refactoring

Answer

Distribution

Question 20

What is the primary goal of normalizing a database?

Accepted Answer

To minimize redundant data and enhance data integrity

Answer

To boost database speed

Answer

To make the database easier to use

Answer

To expand the database's storage capacity

Question 21

Which normal form mandates that all non-key attributes within a table must be fully dependent on the primary key?

Accepted Answer

Second normal form (2NF)

Answer

First normal form (1NF)

Answer

Third normal form (3NF)

Question 22

Which of the following is a potential drawback associated with database normalization?

Accepted Answer

Increased complexity in data structure and relationships

Answer

Accelerated performance in data processing and retrieval

Answer

Enhanced security measures for protecting sensitive data

Answer

Reduced integrity and reliability of data

Question 23

In the context of database normalization, which decomposition technique involves splitting a table horizontally into multiple tables based on a specified condition?

Accepted Answer

Horizontal decomposition

Answer

Decomposition based on attribute characteristics

Answer

Vertical decomposition

Answer

Decomposition based on entity types

Question 24

Which of the following normal forms represents the highest level of normalization?

Accepted Answer

Boyce-Codd normal form (BCNF)

Answer

First normal form (1NF)

Answer

Third normal form (3NF)

Answer

Second normal form (2NF)

Question 25

Which of the following represents a violation of Boyce-Codd normal form (BCNF)?

Accepted Answer

The presence of a transitive dependency among attributes

Answer

The identification of a functional dependency

Answer

The existence of a multivalued dependency

Answer

The occurrence of a partial dependency

Question 26

Which of the following is a **potential** drawback of database normalization?

Accepted Answer

Increased storage space requirements

Answer

Enhanced data consistency

Answer

Improved data access performance

Answer

Simplified data retrieval

Question 27

When denormalizing a database, which of the following factors should be **primarily** considered?

Accepted Answer

Performance requirements

Answer

Data integrity

Answer

Storage limitations

Question 28

Which of the following is a primary technique used to enforce **referential** integrity?

Accepted Answer

Foreign key constraints

Answer

Primary key constraints

Answer

Unique key constraints

Answer

Check constraints

Question 29

Which of the following is a potential **negative** consequence of over-normalization?

Accepted Answer

Increased data fragmentation

Answer

Reduced data redundancy

Answer

Improved data performance

Answer

Enhanced data security

Question 30

For analyzing attribute dependencies within a database table, which data structure is most appropriate?

Accepted Answer

Dependency Diagram

Answer

Decision Tree

Answer

Entity-Relationship Diagram

Answer

Flowchart

Question 31

Normalization of a database may result in what significant disadvantage?

Accepted Answer

Increased data storage space and processing time requirements

Answer

Data redundancy

Answer

Increased data complexity

Answer

Data inconsistency

Question 32

Which of the following is a primary benefit of database normalization?

Accepted Answer

Reduced data redundancy and improved data integrity

Answer

Increased data complexity and redundancy

Answer

Increased storage space and processing time

Answer

Increased data inconsistency and redundancy

Question 33

The Boyce-Codd Normal Form (BCNF) is primarily employed to address and eliminate:

Accepted Answer

Redundancy caused by multi-valued dependencies

Answer

Partial dependencies

Answer

Transitive dependencies

Question 34

Among the following, which is not a valid reason for normalizing a database?

Accepted Answer

Enhancing data security

Answer

Eliminating data redundancy

Answer

Improving data integrity

Answer

Reducing data inconsistency

Question 35

Normalization involves the process of:

Accepted Answer

Decomposing a relation into smaller relations with higher normal forms

Answer

Denormalizing a relation to improve performance

Answer

Combining multiple relations into a single relation

Answer

Referencing relations to create a larger relation

Question 36

Which normal form represents the highest level of data normalization?

Accepted Answer

Boyce-Codd Normal Form (BCNF)

Answer

First Normal Form (1NF)

Answer

Third Normal Form (3NF)

Answer

Second Normal Form (2NF)

Question 37

Which of the following is an advantage of database normalization?

Accepted Answer

Reduced data redundancy

Answer

Increased storage requirements

Answer

Lack of data integrity

Answer

Slower data retrieval

Question 38

What is the primary goal of Boyce-Codd normal form (BCNF)?

Accepted Answer

To eliminate redundancy caused by multi-valued dependencies.

Answer

To ensure that all attributes are atomic and indivisible.

Answer

To eliminate redundancy caused by functional dependencies.

Question 39

Consider the following relation: Student(StudentID, Name, Course, Grade). Which of the following represents a violation of first normal form (1NF)?

Accepted Answer

Name is a multi-valued attribute.

Answer

StudentID is the primary key.

Answer

The relation is in third normal form.

Answer

Grade is a derived attribute.

Question 40

Which of the following techniques is commonly used to decompose a relation into smaller, normalized relations?

Accepted Answer

Functional dependency analysis

Answer

Normalization by synthesis

Answer

Entity-Relationship modeling

Answer

Data flow diagramming

Question 41

Consider the following relation: Order(OrderNumber, CustomerID, ProductID, Quantity). Which of the following represents a violation of second normal form (2NF)?

Accepted Answer

ProductID is dependent on CustomerID.

Answer

CustomerID is the primary key.

Answer

Quantity is dependent on OrderNumber.

Question 42

Which of the following represents the highest normal form that a relation can achieve?

Accepted Answer

Boyce-Codd normal form (BCNF)

Answer

Second normal form (2NF)

Answer

Third normal form (3NF)

Answer

First normal form (1NF)

Question 43

Consider the following relation: Employee(EmployeeID, Name, Department, Salary). Which of the following represents a violation of third normal form (3NF)?

Accepted Answer

Salary is dependent on Department.

Answer

EmployeeID is the primary key.

Answer

The relation is in Boyce-Codd normal form.

Answer

Name is a unique attribute.

Question 44

Which of the following is **NOT** a benefit of database normalization?

Accepted Answer

Increased storage efficiency

Answer

Improved data integrity

Answer

Reduced data redundancy

Answer

Enhanced data consistency

Question 45

To achieve Third Normal Form (3NF), a relation must be in which previous normal form?

Accepted Answer

Second Normal Form (2NF)

Answer

Boyce-Codd Normal Form (BCNF)

Answer

None of the above

Answer

First Normal Form (1NF)

Question 46

Which of the following is the **most** restrictive normal form?

Accepted Answer

Boyce-Codd Normal Form (BCNF)

Answer

Second Normal Form (2NF)

Answer

Third Normal Form (3NF)

Answer

First Normal Form (1NF)

Question 47

What is the primary purpose of a candidate key?

Accepted Answer

To uniquely identify each row in a relation.

Answer

To enforce referential integrity.

Answer

To reduce data redundancy.

Answer

To improve data accessibility.

Question 48

Which of the following is **NOT** a potential disadvantage of database normalization?

Accepted Answer

Improved data security

Answer

Reduced data integrity

Answer

Increased join operations may be required for data retrieval.

Question 49

Consider the relation S(StudentID, StudentName, Major, GPA). Which of the following is a violation of Third Normal Form (3NF)?

Accepted Answer

GPA is dependent on Major.

Answer

The relation is in Boyce-Codd Normal Form (BCNF).

Answer

StudentName is a non-key attribute.

Answer

StudentID is a candidate key.

Question 50

Consider the relation R(A, B, C, D, E) with the following functional dependencies: A → B, C → D, and E → A. Which of the following decompositions results in a database schema in 3NF?

Accepted Answer

R1(A, B, E) and R2(C, D)

Answer

R1(A, C, E) and R2(B, D)

Answer

R1(A, B, C, D) and R2(E)

Answer

R1(A, B, C) and R2(D, E)

Question 51

Which of the following is a potential drawback of database normalization?

Accepted Answer

Increased processing overhead for certain operations

Answer

Improved data security

Answer

Guaranteed data consistency

Question 52

What is the main goal of database normalization?

Accepted Answer

To eliminate data redundancy and improve data integrity

Answer

To minimize the number of tables in a database schema

Answer

To enhance database performance