What is Normalization?
Database designed based on ER model may have some amount of inconsistency, ambiguity and redundancy. To resolve these issues some amount of refinement is required. This refinement process is called as Normalization.
Normalization is a technique for producing a set of relations with desirable properties, given the data requirements of an enterprise.
The process of normalization was first developed by E. F. Codd.
Normalization is often performed as a series of tests on a relation to determine whether it satisfies or violates the requirements of a given normal form.
Advantages of Normalization
- Less storage space
- Reduces data redundancy in a database
- It eliminates serious manipulation anomalies.
- Flexible structure
Given a relation schema, we need to decide whether it is a good design or we ne decompose it into smaller relations. To make such a decision, several normal forms hav proposed.
The normal forms based on FDs are first normal form (1NF), second normal form(2NF) normal form (3NF), Boyce-Codd normal form (BCNF), Fourth normal form(4NF), Fifth n form(5NF or PJNF). 8:13