Normalization with ERD

What is Normalization?

• Normalization is the process of organizing the data in the database.

• Normalization divides the larger table into smaller and links them using relationships.

• The normal form is used to reduce redundancy from the database table.

• Normalization is a saving function from the database

Why Normalize a Database?

• • Make the database more efficient

• • Reduce the storage space that a database takes up

• To update data from the database.

• Make the database more efficient

What is the main purpose of normalization in database design?

• To reduce redundancy

• To increase redundancy

• To ensure faster queries

• To decrease database size

Which normal form ensures that there are no repeating groups of data?

• 2NF

• 3NF

• 1NF

• BCNF

Answer explanation

first normal form (1NF)

A table is in first normal form (1NF) if it meets the following criteria: The data are stored in a two-dimensional table. There are no repeating groups.

In a normalized database, which normal form ensures that there are no partial dependencies?

• 1NF

• 2NF

• 3NF

• BCNF

Answer explanation

A relation is in 2NF if it has No Partial Dependency, i.e., no non-prime attribute (attributes which are not part of any candidate key) is dependent on any proper subset of any candidate key of the table

What does the process of normalization aim to achieve?

• Improve query speed

• Eliminate anomalies and redundancy

• Reduce data size

• Create complex relationships

In an ERD, what symbol typically represents an entity?

• Circle

• Diamond

• Rectangle

• Oval

What is the purpose of a foreign key in a database?

• To uniquely identify records

• To enforce relationships between tables

• To store duplicate data

• To create indexes

Which of the following is a characteristic of 1NF?

• Elimination of transitive dependencies

• No repeating groups of data

• No partial dependencies

• Use of composite keys

Answer explanation

A table is in the first normal form (1NF) if all the key attributes are defined and there are no repeating groups in the table. All attributes are dependent or partially dependent on the primary key.

What type of relationship does a crow's foot represent in an ERD?

• One-to-one

• One-to-many

• Many-to-many

• Self-referencing