A NEW DEFINITION OF FUZZY FUNCTIONAL DEPENDENCY IN FUZZY RELATIONAL DATABASES

The need to incorporate and treat information given in fuzzy terms in Relational Databases has concentrated a great effort in the last years . This article focuses on the treatment of functional dependencies (f. d.) between attributes of a relation scheme. We review other approache s to this problem and present some of its missfunctions concerning int uitive properties a fuzzy extension of f.d. should verify. Then we int roduce a fuzzy extension of this concept to overcome the previous anom alous behaviors and study its properties. Of primary interest is the c ompleteness of our fuzzy version of Armstrong axioms in order to deriv e all the fuzzy functional dependencies logically implied by a set of f.f.d. just using these axioms. (C) 1994 John Wiley & Sons, Inc.