Understanding Database Normalization

What is the primary purpose of database normalization?

• To reduce data redundancy and improve data integrity.

• To simplify database queries and enhance performance.

• To increase data duplication and decrease data integrity.

• To eliminate all data from the database entirely.

Define the First Normal Form (1NF).

• A table is in First Normal Form (1NF) if it contains nested tables within its columns.

• A table is in First Normal Form (1NF) if it has no primary key defined.

• A table is in First Normal Form (1NF) if it allows duplicate values in a column.

• A table is in First Normal Form (1NF) if it contains only atomic values, each column has unique names, and all entries in a column are of the same data type.

What are the requirements for a table to be in 1NF?

• A table is in 1NF if it requires a specific order for rows.

• A table is in 1NF if it has atomic values, single type per column, unique column names, and order independence.

• A table is in 1NF if it allows duplicate column names.

• A table is in 1NF if it has multiple data types per column.

Explain the concept of atomicity in 1NF.

• Atomicity in 1NF allows for multiple values in a single column.

• Atomicity in 1NF means that each row must be unique and contain multiple attributes.

• Atomicity in 1NF means that each column must contain only atomic, indivisible values.

• Atomicity in 1NF refers to the ability to group related data together.

What is the Second Normal Form (2NF)?

• A table is in Second Normal Form (2NF) if it is in First Normal Form (1NF) and all non-key attributes are fully functionally dependent on the primary key.

• A table is in Second Normal Form (2NF) if all attributes are dependent on a single non-key attribute.

• A table is in Second Normal Form (2NF) if it contains no duplicate rows.

• A table is in Third Normal Form (3NF) if it has no transitive dependencies.

What is the significance of removing partial dependencies in 2NF?

• It eliminates redundancy and ensures all non-key attributes depend on the entire primary key.

• It allows for multiple primary keys in a relation.

• It increases the number of non-key attributes in a table.

• It ensures that all attributes are dependent on a single non-key attribute.

How do you determine if a table is in 2NF?

• A table is in 2NF if it has no duplicate rows.

• A table is in 2NF if it contains at least one primary key.

• A table is in 2NF if all attributes are dependent on the entire table.

• A table is in 2NF if it is in 1NF and all non-key attributes are fully functionally dependent on the primary key.

Define the Third Normal Form (3NF).

• A table is in First Normal Form if it has no duplicate rows.

• A table is in Third Normal Form if it contains at least one foreign key.

• A table is in Third Normal Form (3NF) if it is in Second Normal Form and all non-key attributes are functionally dependent only on the primary key.

• A table is in Third Normal Form if all attributes are dependent on each other.

What is the role of transitive dependencies in 3NF?

• Transitive dependencies are only relevant in 1NF and 2NF.

• Transitive dependencies can exist in 3NF without any issues.

• Transitive dependencies are required in 3NF to maintain data integrity.

• Transitive dependencies must be eliminated in 3NF to ensure non-prime attributes depend only on the primary key.

How can you convert a table from 2NF to 3NF?

• Remove transitive dependencies and ensure all non-key attributes depend only on the primary key.

• Eliminate all foreign keys from the table.

• Combine multiple tables into one larger table.

• Add more non-key attributes to the table.