数据依赖中传递函数依赖的研究与探讨  

Research and Discussion of Transitive Functional Dependency in the Data Dependency

作　　者：吕俊亚[1] 卢植衡[1] 

机构地区：[1]河南财经政法大学,河南郑州450002

出　　处：《安徽农业科学》2012年第8期4467-4468,4472,共3页Journal of Anhui Agricultural Sciences

摘　　要：数据依赖是关系数据理论的核心,是关系模式分解的关键。介绍了码、候选码、主属性、非主属性的概念和数据依赖的相关概念以及数据依赖对规范化的重要性,从数据依赖本质和第1范式到第5范式间的包含关系等不同的角度对传递依赖进行了系统分析,同时又对当前几个主要的普遍使用的数据库系统原理教材中的传递数据依赖定义进行了分析,从而给出了传递数据依赖的准确的定义,并且提出了部分依赖是特殊的传递依赖的观点,并加以论证。Data dependency is the core of the theory of relational data and it is the key to relationship mode decomposition. The concept of the code, the candidate code, the main property, the non -primary attributes and the data dependence were introduced. It was also described that data dependence is important to the normalization. The transfer dependence was analyzed from different perspectives including data dependent na- ture and the first paradigm to the fifth paradigm. At the same time, the concept of the transfer of data that is used on the current main principles of database systems was analyzed and an accurate definition of transfer data dependent. Finally, the view that some of the dependency is a special one of the transfer dependence was put forward and demonstrated.

关 键 词：数据依赖 函数依赖 部分函数依赖 传递函数依赖 候选码 

分 类 号：S11[农业科学—农业基础科学] O174[理学—数学]