Data dependencies in fuzzy object oriented
databases model based on hedge algebra

Abstract. The single most important concept in database schemas design is that of a functional dependency. A functional dependency describes the relationship among attributes and is one of the key concepts used in the normalization. On the basic of fuzzy object-oriented databases model with hedge algebra has been studied in [2], in this paper, we introduce the study of the form of data dependencies, including fuzzy functional dependency in object class, fully fuzzy functional dependency, partial fuzzy functional dependency, transitive fuzzy functional dependency and fuzzy functional dependency with quanifier in natural languages. Based on the concepts of fuzzy functional dependencies, the paper also propose the normal forms of fuzzy object-class in the model.