模糊关系数据库系统中的函数依赖与多值依赖

Fuzzy Functional and Multivalued Dependencies of Fuzzy Relational Database Systems

用模糊关系数据模型来描述不分明的模糊数据是关系数据库理论发展中的一个重要的新课题。本文用模糊等价关系及其隶属函数来描述模糊函数依赖与多值依赖,看出经典数据依赖是模糊数据依赖的特例。并且证明相应于Armstrong公理的一套模糊数据依赖的推理规则是正确、完备的。

It is an important topic in the theory of relational databases that the fuzzy relational data model is used to representing ambiguities in data values. In this paper, fuzzy functional and multivalued dependencies are represented by means of fuzzy equivalent relation. The functional and multivalued dependencies in a classical relational database can be viewed as a special case of fuzzy functional and multivalued dependencies. This paper will show that the inference rules for fuzzy data dependencies, which are similar to Armstrong's Axions for classical case, are sound and complete.