Fuzzy Functional Dependencies (FFDs) as Integrity Constraints

  • Guoqing Chen
Part of the The Springer International Series on Advances in Database Systems book series (ADBS, volume 15)


Since functional dependency (FD) is an important notion of nowadays database technology, its fuzzy extension has attracted a lot of attention, especially since the late 1980’s (Buckles and Petty, 1982; Prade and Testemale, 1983; Zemankova and Kandel, 1984; Raju and Majumdar, 1988; Kiss, 1990; Chen, Kerre and Vandenbulcke, 1991,1995; Dubois and Prade, 1992; Cubero and Vila, 1994). Consequently, different definitions of fuzzy functional dependencies (FFDs) emerged, resulting from the application of fuzzy logic to the conventional FD in various manners, and to different extents. Usually, each of such definitions of fuzzy functional dependencies is associated with its own framework of fuzzy database model (fuzzy data representation), therefore is normally relevant merely within the framework, although there always exist basic properties and essential characteristics that need or are desirable to possess.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Buckles BP, Petry FE. A fuzzy representation of data for relational databases. Fuzzy Sets and Systems 1982; 7:213–226.zbMATHCrossRefGoogle Scholar
  2. Chen GQ, Vandenbulcke J, Kerre EE. A step towards the theory of fuzzy database design. Proceedings of IFSA’91, Brussels, 1991; 44–47.Google Scholar
  3. Chen, Guoqing. “Fuzzy Functional Dependencies and a Series of Design Issues of Fuzzy Relational Databases’91. In P. Bosc and J. Kacprzyk (eds.), Studies in Fuzziness: fuzzy sets and possibility theory in database management systems, Physica-Verlag (Springer-Verlag Group), 1995; 166–185.Google Scholar
  4. Cubero JC, Vila MA. A new definition of fuzzy functional dependency in fuzzy relational databases. International Journal of Intelligent Systems 1994;.9(5): 441–448.CrossRefGoogle Scholar
  5. Dubois D, Prade H. Generalized dependencies in fuzzy data bases. Proceedings of IPMU’92, Palma, 1992;.263–266.Google Scholar
  6. Kiss A. λ-decomposition of fuzzy relational databases. Proceedings of International Workshop on Fuzzy Sets and Systems, Visegrad, Hungray, 1990.Google Scholar
  7. Prade H, Testemale C. Generalizing database relational algebra for the treatment of incomplete/uncertain information and vague queries. Proceedings of 2nd NAFIPS Workshop, Schenectady, NY, 1983.Google Scholar
  8. Raju KVSVN, Majumdar AK. Fuzzy functional dependencies and lossless join decomposition of fuzzy relational database systems. ACM Transactions on Database Systems 1988; 13(2): 129–166.CrossRefGoogle Scholar
  9. Zemankova; M.; Kandel, A. Fuzzy Relational Database — a key to expert systems. Verlag TUV Rheinland, 1984.Google Scholar

Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • Guoqing Chen
    • 1
  1. 1.School of Economics and ManagementTsinghua UniversityBeijingChina

Personalised recommendations