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Normalization

20 十月, 2015 - 09:31

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.