NORMALIZATION M.Janarth

Computing Batch

No:XXIV

Content What is normalization? Process of Normalization First Normal Form (1NF) Second Normal Form (2NF) Third Normal Form (3NF) More Normalized forms Summary Reference

What is normalization?

Normalization is the process of efficiently organizing data in a database

Normalization is used for mainly two purpose

-eliminating useless data -ensuring data

dependencies make sense . 

Process of Normalization

If a database design is not perfect it may contain anomalies

Managing a database with anomalies -Update anomalies -Deletion anomalies -Insert anomalies

First Normal Form (1NF) This is a normal form of data

Re arrange the data to convert it to first normal form

Second Normal Form (2NF) Remove subsets of data that apply to

multiple rows of a table and place them in separate tables.

Create relationships between these new tables and their predecessors.

Third Normal Form (3NF) Remove columns that are

not dependent upon the primary key.

The transitive functional dependency should be removed from the table

More Normalized forms

In Boyce-Codd Normal Form (BCNF or 3.5NF) Every determinant must be a candidate key.

In Fourth Normal form (4NF) A relation is in 4NF if it has no multi-valued dependencies.

Summary

Reference Database Normalization Basics

available at <http://databases.about.com/od/specificproducts/a/normalization.htm>accessed on 29/01/2015

Normalization of database available at <http://www.studytonight.com/dbms/database-normalization.php> accessed on 26/01/2015

DBMS Normalization available at <http://www.tutorialspoint.com/dbms/database_normalization.htm>accessed on 26/01/2015