Normalization

Assignment 2

Normalization

Table of Contents

1. Introduction to Normalization

2. Steps to Convert Database Table into First, Second and Third Normal Forms

3. Illustration – Reason to Convert Database Table into First, Second and Third Forms

4. Explain Situations when De-Normalization is Acceptable with an Illustration

5. Impact of Business Rules on Database Normalization and Decision to De- normalize it

1. Normalization

The process to organize a data in a database efficiently is termed as Normalization. With an aim to eliminate redundant data and ensuring the logic of data dependency, normalization is a process used by various businesses and colleges for efficient data recording. It helps in storing the data logically and reduces the space taken by it.

To normalize a database, one uses a prescribed set of series which are termed as normal forms. There are typically three normal forms – first or 1NF, second or 2NF, third or 3NF. Practically only these three forms are applied, however sometimes 4NF and 5NF can be used.

2. Steps to Convert Database Table into First, Second and Third Normal Forms

To convert an unorganized database table into first, second and third normal forms; following steps shall be applied:

2.1 Conversion to First Normal Form

While converting the database table to 1NF, you should follow these guidelines –

• Remove duplicity by eliminating those columns from the database table that appear more than once.
• Related data should be organized in separate tables and classify the primary key i.e. recognise each row with a distinct column or set of columns.

2.2 Conversion to Second Normal Form

To convert to 2NF, follow these guidelines –

• You should meet the guidelines of 1NF
• Eliminate the subsets of data given in multiple rows and group them in separate tables
• Using foreign keys for creating association between the new table and its predecessors.

2.3 Conversion to Third Normal Form

To convert database to 3NF, following guidelines need to be followed –

• You need to satisfy the requirements of 2NF
• Eliminate those columns that are not reliant on the primary key

3.  Illustration – Reasons for Conversion of Database to 1NF, 2NF and 3NF.

Let’s illustrate an example that shows the reason to convert the database table to 1NF, 2 NF and 3NF.