What is Normalization?
Normalization is a database design technique which organizes tables in a manner that reduces redundancy and dependency of data.
It divides larger tables to smaller tables and link them using relationships.
In this tutorial, you will learn-
The inventor of the relational model Edgar Codd proposed the theory of normalization with the introduction of First Normal Form and he continued to extend theory with Second and Third Normal Form. Later he joined with Raymond F. Boyce to develop the theory of Boyce-Codd Normal Form.
Theory of Data Normalization in Sql is still being developed further. For example there are discussions even on 6th Normal Form. But in most practical applications normalization achieves its best in 3rd Normal Form. The evolution of Normalization theories is illustrated below
1st Normal Form >> 2nd Normal Form >> 3rd Normal Form >>4th Normal Form >> 5th Normal Form >>6th Normal Form
Database Normalization Examples –
Assume a video library maintains a database of movies rented out. Without any normalization all information is stored in one table as shown below.
Further We shall discuss on different normal forms in detailed: