DBMS Normalization Quiz

What is the main purpose of database normalization?

• To increase data redundancy

• To eliminate data redundancy and ensure logical data storage

• To decrease data security

• To create larger tables

Answer explanation

The main purpose of database normalization is to eliminate data redundancy and ensure logical data storage.

Who proposed the theory of normalization?

• Raymond F. Boyce

• Marcus Allen

• Edgar Codd

• Alan Turing

Answer explanation

The theory of normalization was proposed by Edgar Codd, making him the correct choice out of the options provided.

What does 1NF (First Normal Form) ensure?

• Each column contains atomic values and each record is unique

• No multi-valued dependencies

• Elimination of transitive dependency

• All non-key attributes are fully functional on the primary key

Answer explanation

Each column contains atomic values and each record is unique

What is a primary key?

• A column that can be null

• A column that references another table

• A column that uniquely identifies a record in a table

• A column that can have duplicate values

Answer explanation

A primary key is a column that uniquely identifies a record in a table, distinguishing it from other records.

What is a composite key?

• A primary key composed of multiple columns

• A foreign key composed of multiple columns

• A key that can be null

• A key that is not unique

Answer explanation

A composite key is a primary key composed of multiple columns, making it unique in combination. It helps uniquely identify each row in a table.

What is the main rule of 2NF (Second Normal Form)?

• Be in 1NF and have no repeating groups

• Be in 1NF and have a single column primary key

• Be in 1NF and have no transitive dependencies

• Be in 1NF and have no multi-valued dependencies

Answer explanation

The main rule of 2NF is to be in 1NF and have a single column primary key.

What is a foreign key?

• A key that references the primary key of another table

• A key that uniquely identifies a record in a table

• A key that is always unique

• A key that can be null

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 a transitive functional dependency?

• When a table is in 1NF

• When a foreign key references a primary key

• When a primary key is composed of multiple columns

• When changing a non-key column might cause another non-key column to change

Answer explanation

When changing a non-key column might cause another non-key column to change

What is the main rule of 3NF (Third Normal Form)?

• Be in 2NF and have no repeating groups

• Be in 2NF and have a single column primary key

• Be in 2NF and have no multi-valued dependencies

• Be in 2NF and have no transitive dependencies

Answer explanation

Be in 2NF and have no transitive dependencies

What does BCNF (Boyce-Codd Normal Form) address?

• Temporal data

• Anomalies not handled by 3NF

• Multi-valued dependencies

• Projection-Join Normal Form

Answer explanation

BCNF addresses anomalies not handled by 3NF, making it a more stringent normalization form.