Normalization of Database

Normalization is a process for assigning attributes to entities. It reduces data redundancies and helps eliminate the data anomalies.
Normalization works through a series of stages called normal forms:
First normal form (1NF)
Second normal form (2NF)
Third normal form (3NF)
Fourth normal form (4NF)
The highest level of normalization is not always desirable.


Denormalization

Normalization is only one of many database design goals.
Normalized (decomposed) tables require additional processing, reducing system speed.
Normalization purity is often difficult to sustain in the modern database environment. The conflict between design efficiency, information requirements, and processing speed are often resolved through compromises that include denormalization.