DF关系数据库的函数依赖研究
Research on Functional Dependencies of Dynamic Fuzzy Relational Database
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摘要: 数据间的函数依赖关系一直是关系数据库理论研究中的重要课题,同样,DF关系数据库中也存在着函数依赖关系.首先,基于DF关系理论给出了DF关系数据模型的定义,并介绍了属性值的表示方法;然后,用动态模糊等价关系及其隶属函数来描述动态模糊函数依赖,给出了DF数据库中函数依赖的基本定义,以及基于DF蕴涵关系的公理系统,并证明其推理规则是正确和完备的;最后讨论了DF关系的规范化设计.Abstract: The functional dependency in data is an important topic in the theory of relational databases.Similarly,the functional dependency also existed in the DF relational database.First,based on dynamic fuzzy relation,dynamic fuzzy relational data model is presented;the representation of dynamic fuzzy data value is introduced.Then,dynamic fuzzy functional dependency is represented by means of dynamic fuzzy equivalent relation and its membership function;the inference rules for dynamic fuzzy functional dependency are described and proved.Finally,the normalization design of dynamic fuzzy relations is discussed.
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