The decomposition versus synthetic approach to relational database design
Ronald Fagin · 1977
Two of the competing approaches to the logical design of relational databases are the third normal form decomposition approach of Codd and the synthetic approach of Bernstein and others. The synthetic approach seems on the surface to be the more powerful; unfortunately, to avoid serious problems, a nonintuitive constraint (the "uniqueness " of functional dependencies) must be assumed. We demonstrate the fourth normal form approach, which not only can deal with this difficulty, but which is also more powerful than either of the earlier approaches. The input of the new method includes attributes (potential column names), along with semantic information in the form of functional and multivalued dmendencies: the outDut is a "8ood "- (fourth normal form). lorrical- desinn. The new method 1 is semi-automatic, which is especially helpful in the case of a very large database with many attributes that interrelate in complex ways.