关联度与关系模式分解满足P_(BC)且无α环的关系

The Relation Between Relevancy Degree and Decomposition of Relation Schema Meeting P_(BC) and No-αRing

一个数据库模式分解为满足保持函数依赖、无损联接性、BCNF且无α环是数据库理论和应用研究的重要问题之一。通过分析无α环的分解特性使我们得知,要达到无α环的分解,必须研究这种分解与关联度之间的关系。论文给出了这种关系。

The decomposition of a database schema to meet preserving functional dependency,lossless join,BCNF and no-αring is one of the important problems of the theoretical research of a database and its application.By analyzing the decomposition feature of no-αring,in order to gain decomposition of no-αring,it's necessary to study the relation between decomposition and relevancy degree.This paper presents the relation.