SWITCHING-ALGEBRAIC ANALYSIS OF RELATIONAL DATABASES

There is an established equivalence between relatio nal database Functional Dependencies (FDs) and a fragment of switching algebra that is built typical ly of Horn clauses. This equivalence pertains to bo th concepts and procedures of the FD relational databa se domain and the switching algebraic domain. This study is an exposition of the use of switching -algebraic tools in solving problems typically encountered in the analysis and design of relationa l databases. The switching-algebraic tools utilized include purely-algebraic techniques, purely-visual techniques employing the Karnaugh map and intermediary techniques employing the variable-ente red Karnaugh map. The problems handled include; (a) the derivation of the closure of a Dep endency Set (DS), (b) the derivation of the closure of a set of attributes, (c) the determination of all c andidate keys and (d) the derivation of irredundant dependency sets equivalent to a given DS and conseq uently the determination of the minimal cover of such a set. A relatively large example illustrates the switching-algebraic approach and demonstrates i ts pedagogical and computational merits over the tradi tional approach.