Database Normalization

Database Normalization

^l        Database normalization is the process of removing redundant data from your tables in to improve storage efficiency, data integrity, and scalability.

^l        In the relational model, methods exist for quantifying how efficient a database is. These classifications are called normal forms (or NF), and there are algorithms for converting a given database between them.

^l        Normalization generally involves splitting existing tables into multiple ones, which must be re-joined or linked each time a query is issued.

Levels of Normalization

•         Levels of normalization based on the amount of redundancy in the database.

•         Various levels of normalization are:

–  First Normal Form (1NF)

–  Second Normal Form (2NF)

–  Third Normal Form (3NF)

–  Boyce-Codd Normal Form (BCNF)

–  Fourth Normal Form (4NF)

–  Fifth Normal Form (5NF)

–  Domain Key Normal Form (DKNF)

Most databases should be 3NF or BCNF in order to avoid the database anomalies.