Understanding Database Normalization

Isla is organizing a database for her school project. What is the main goal of First Normal Form?

• To ensure that all attributes in a table are atomic and to eliminate duplicate records.

• To create foreign key relationships between tables.

• To ensure all records in a table are unique.

• To group related tables together.

Answer explanation

The main goal of First Normal Form is to ensure that all attributes in a table are atomic, meaning they cannot be divided further, and to eliminate duplicate records, which helps maintain data integrity.

In a database for a school project, which of the following is a requirement for a table to be in Second Normal Form?

• The table must have at least three attributes.

• All non-key attributes must be fully functionally dependent on the primary key.

• No attribute can be null.

• All attributes must be dependent on at least one foreign key.

Answer explanation

For a table to be in Second Normal Form, all non-key attributes must be fully functionally dependent on the primary key. This ensures that there are no partial dependencies, which is essential for reducing redundancy.

In a database used by Elijah's school, what does Third Normal Form aim to eliminate?

• Transitive dependencies

• Redundant data

• Duplicate records

• Unnecessary indexes

Answer explanation

Third Normal Form (3NF) aims to eliminate transitive dependencies, which occur when a non-key attribute depends on another non-key attribute. This helps ensure that all attributes are only dependent on the primary key.

In a database for a school, define Boyce-Codd Normal Form in relation to functional dependencies as it applies to student records.

• A relation is in Boyce-Codd Normal Form if it has no primary key.

• A relation is in Boyce-Codd Normal Form if, for every functional dependency X -> Y, X is a superkey.

• A relation is in Boyce-Codd Normal Form if all attributes are unique.

• A relation is in Boyce-Codd Normal Form if every attribute is dependent on the primary key.

Answer explanation

A relation is in Boyce-Codd Normal Form if, for every functional dependency X -> Y, X is a superkey. This ensures that all non-trivial functional dependencies are preserved, preventing redundancy and anomalies.

Anika is working on a project that involves managing a large database of student records. She wants to ensure that the data is organized efficiently. What is data normalization and why is it important?

• Data normalization is a method for encrypting sensitive information.

• Data normalization is only necessary for small databases.

• Data normalization increases data redundancy and slows down queries.

• Data normalization is important because it minimizes data redundancy, ensures data integrity, and improves query performance in databases.

Answer explanation

Data normalization is crucial as it reduces data redundancy, maintains data integrity, and enhances query performance, making databases more efficient and reliable.

Michael is designing a database for his school project. List one goal of normalization in database design.

• To enhance data retrieval speed.

• To increase data duplication.

• To simplify data relationships.

• To reduce data redundancy.

Answer explanation

One goal of normalization is to reduce data redundancy, which minimizes duplicate data entries and ensures data integrity. This helps maintain a more efficient and organized database structure.

Anika is organizing a database for her school project. How does First Normal Form handle repeating groups?

• First Normal Form requires all columns to be of the same data type.

• First Normal Form eliminates the need for primary keys.

• First Normal Form handles repeating groups by ensuring that each column contains atomic values and creating separate rows for each instance.

• First Normal Form allows multiple values in a single column.

Answer explanation

First Normal Form (1NF) addresses repeating groups by ensuring that each column contains atomic values, meaning each value is indivisible. It also requires that each instance of a repeating group is represented in separate rows, maintaining data integrity.

Ethan is designing a database for his school project. What is a characteristic of a table in Second Normal Form?

• All attributes can be partially dependent on the primary key.

• There are no non-key attributes in the table.

• The primary key can be a composite of non-key attributes.

• All non-key attributes are fully functionally dependent on the primary key.

Answer explanation

In Second Normal Form, all non-key attributes must be fully functionally dependent on the primary key, meaning they cannot depend on only part of a composite key. This ensures data integrity and eliminates partial dependencies.

Mia is studying database design and wants to understand the significance of removing transitive dependencies in Third Normal Form.

• To ensure that all attributes are stored in a single table.

• To increase the number of attributes in a table.

• The significance of removing transitive dependencies in Third Normal Form is to eliminate redundancy and ensure that non-key attributes depend only on the primary key, enhancing data integrity.

• To allow multiple primary keys in a table.

Answer explanation

The significance of removing transitive dependencies in Third Normal Form is to eliminate redundancy and ensure that non-key attributes depend only on the primary key, enhancing data integrity.

In a database for a school project, Oliver is trying to understand the difference between Second Normal Form and Third Normal Form. What should he know?

• 2NF focuses on eliminating partial dependencies, while 3NF eliminates transitive dependencies.

• 2NF eliminates transitive dependencies, while 3NF focuses on eliminating partial dependencies.

• Both 2NF and 3NF aim to eliminate redundancy in database design.

• 2NF is concerned with ensuring all attributes are fully functional dependent on the primary key.

Answer explanation

The correct choice states that 2NF eliminates partial dependencies, ensuring all non-key attributes are fully dependent on the primary key, while 3NF focuses on removing transitive dependencies, which can lead to redundancy.