摘要
讨论了两个归并依赖之间的直接决定的关系 ,给出了一个归并依赖直接决定集的求法 ,同时讨论了当函数依赖集为无内部冲突时 ,直接决定集的性质。
This paper discusses the direct determined relationship between two merger dependency, and gives the solution for a direct determined set of a merger dependency. It also discusses the properties of a direct determined set of a merger dependency when the set of function dependency is non interior conflict.
基金
湖北省自然科学基金!资助项目 ( 9752 0 1812 9)
关键词
关系数据库
函数依赖
左部集
直接决定集
relational databases
functional dependency
left part set
direct determined set Yang Guanglin Lect.
School of Information Science and Engineering, Yanshan University, Qinghuangdao 066000, China.
