A consideration on normal form of not-necessarily-normalized relation in the relational data model

Abstract

In this paper definitions of unnormalized relation, functional dependency on it and Normal Form are presented. The Normal Form plays a key role in our relational data model in which unnormalized relations are admitted as does the Third Normal Form of Codd in the data model of normalized relation. Properties pertaining to Normal Form are discussed emphasizing comparison with 3NF along with analysis of some typical examples. Similarity and dissimilarity between new functional dependency and Fagin's multivalued depend-ency are also discussed and presented in the form of proposition. 1. INTRODUCTION 2. AN EXTENSION OF F!lNCTIONAL DEPENDENCY Codd proposed a relational model of data in his earlier paper [l] and developed his idea on normali-zation of relational data model in his succeeding oaoers 12 and 41. He defined three tvoes of normal