A hierarchical method for synthesizing relations

There are two basic approaches in the normalization theory of relational databases. One approach is the decomposition of large relation schemes into smaller relation schemes. A required criteria for a satisfactory decomposition is the lossless join property. The other approach is to synthesize a set of relation schemes from a given set of functional dependencies that are assumed to hold for a universal relation scheme. The synthesized relation schemes are easily identified once a minimal cover of the given set of functional dependencies is obtained. This paper presents another method for synthesizing relation schemes without finding a minimal cover. Starting with a given set of functional dependencies, a partial order graph can be defined. Using the partial order graph and any method for finding keys of relation schemes, a systematic method for synthesizing relation schemes is outlined. The method is easy to implement. However, no programming technique is suggested in this paper.