Normalization is the branch of relational theory providing design insights. The goals of normalization are:
- be able to characterize the level of redundancy in a relational schema
- provide mechanisms for transforming schemas to remove redundancy
Normalization draws heavily on the theory of functional dependencies. Normalization theory defines six normal forms (NFs). Each normal form involves a set of dependency properties that a schema must satisfy and each gives guarantees about presence/absence of update anomalies. That means higher normal forms have less redundancy so less update problems.