Normalization in DBMS

Normalization is a process of organizing the data in database to avoid data redundancy, insertion anomaly, update anomaly & deletion anomaly.


Normalization

Here are the most commonly used normal forms:
First normal form(1NF)
Second normal form(2NF)
Third normal form(3NF)
Boyce & Codd normal form (BCNF)

First Normal Form
As per First Normal Form, no two Rows of data must contain repeating group of information i.e each set of column must have a unique value. Each table should be organized into rows, and each row should have a primary key that distinguishes it as unique.

Second Normal Form
A table is said to be in Second Normal Form if both the following conditions hold:
It is in first normal form.
All non-key attributes are fully functional dependent on the primary key.

Third Normal form
A table is in a third normal form when the following conditions are met −
It is in second normal form.
All non-primary fields are dependent on the primary key.

Boyce and Codd Normal Form
It is an advance version of 3NF
A database table is in BCNF if and only if there are no non-trivial functional dependencies of attributes on anything other than a superset of a candidate key.
BCNF is also sometimes referred to as 3.5NF, or 3.5 Normal Form.

Denormalization 

Denormalization is the technique of combining the data into a single table to make data retrieval faster.