DBMS Normalization Quiz

What is the main purpose of normalization in SQL?

• To decrease data consistency

• To create larger tables

• To eliminate redundant data and ensure logical data storage

• To increase data redundancy

Answer explanation

To eliminate redundant data and ensure logical data storage

Who proposed the theory of normalization?

• Raymond F. Boyce

• Edgar Codd

• Marcus Allen

• Donald Knuth

Answer explanation

Edgar Codd proposed the theory of normalization.

Which normal form ensures that each column contains atomic values and each record is unique?

• 1NF

• 2NF

• BCNF

• 3NF

Answer explanation

1NF ensures that each column contains atomic values and each record is unique.

What is a primary key?

• A key that uniquely identifies a database record

• A key that can be null

• A key that can have duplicate values

• A key that is used to connect tables

Answer explanation

A primary key is a key that uniquely identifies a database record, making it a crucial element in ensuring data integrity and uniqueness.

Which normal form eliminates transitive dependency?

• 3NF

• 4NF

• 2NF

• 1NF

Answer explanation

3NF eliminates transitive dependency by ensuring that every non-prime attribute is non-transitively dependent on every candidate key.

What is a composite key?

• A key that is used to connect tables

• A key composed of multiple columns used to identify a record uniquely

• A key that can be null

• A key that is always unique

Answer explanation

A composite key is a key composed of multiple columns used to identify a record uniquely, making it different from a single-column key.

What is a foreign key?

• A key that uniquely identifies a database record

• A key that references the primary key of another table

• A key that can be null

• A key that is always unique

Answer explanation

A foreign key is a key that references the primary key of another table, establishing a relationship between the two tables.

What is one disadvantage of normalization?

• Increased complexity

• Improved data consistency

• Reduced data redundancy

• Improved query performance

Answer explanation

One disadvantage of normalization is increased complexity due to the need for managing multiple tables and relationships.