函数依赖集F有内部冲突的判定问题研究

Reserch on Deciding Problem of Inside Conlict in Functional Dependency Set F

在讨论数据库模式R〈W ,F〉的无α环分解时 ,需要判定FD集F是否有内部冲突 ;在讨论无 β ,γ环的分解时也需要判定是否有内部冲突 为此 ,应当首先给出归并依赖集的二元组集合、闭包等概念 ;分别给出求解二元组集合及其闭包的多项式算法 在此基础上 ,讨论FD集F有内部冲突时的特征和相关条件 ,给出相应的有内部冲突的判定定理和算法 。

When discussing the decomposition of the database schema R〈W,F〉 without α cycle, it is necessary to decide whether the FD set F has inside conflicts It's also necessary to decide whether the FD set F has inside conflicts when discussing the decomposition without β cycle or γ cycle Therefore, the concepts such as the 2 tuple set and closure of merge dependency set should first be given The multinominal algorithm to solve the 2 tuple set and its closure is also presented On this basis, the properties and relative conditions of the FD set F with inside conflicts is discussed The corresponding deciding theorem and algorithms with inside conflicts are presented and the algorithm is proven and analyzed The theorem and algorithm of the inside conflict and the proof and analysis of the algorithm are also given