Problem Decomposition Method to Compute an Optimal Cover for a Set of Functional Dependencies

The paper proposes a problem decomposition method for building optimal cover for a set of functional dependencies to decrease the solving time. At the beginning, the paper includes an overview of the covers of functional dependencies. There are considered definitions and properties of non redundant covers for sets of functional dependencies, reduced and canonical covers as well as equivalence classes of functional dependencies, minimum and optimal covers. Then, a theoretical tool for inference of functional dependencies is proposed, which possesses the uniqueness property. And finally, the set of attributes of the relational schema is divided into equivalence classes of attributes that will serve as the basis for building optimal cover for a set of functional dependencies.