What is Normalizing?

Normalizing is the process of organizing data to minimizing redundancy.

If a database design is not perfect, it may contain anomalies, which are like a bad dream for any database administrator. Managing a database with anomalies is next to impossible

There are three main anomalies;

Update anomalies

when we try to update one data item having its copies scattered over several places, a few instances get updated properly while a few others are left with old values

Deletion anomalies

We tried to delete a record, but parts of it was left undeleted because of unawareness, the data is also saved somewhere else

Insert anomalies

We tried to insert data in a record that does not exist at all.

Normalization is a method to remove all these anomalies and bring the database to a consistent state.

First Normal Form

In a database, there must be only one atomic-value in a column/attribute.

Second Normal Form

In the second normal form, the relational schema should have in 1NF. And there should not have any partial dependencies.

Third Normal Form

In the third normal form, the relational schema should have in 2NF. And there should not have any transitive dependencies.

Boyce-Codd Normal Form

In the Boyce-Codd normal form, the relational schema should have in 3NF. And there should not have any prime attribute that depends on non-prime attribute.