基数为M的候选关键字求解的多项式算法存在性研究

RESEARCH ON THE EXISTENCE OF A POLYNOMIAL-TIME ALGORITHM TO FIND THE CANDIDATE KEY WHOSE CARDINALITY IS M

本文在文献［３］的基础上，详细且深入讨论了构成候选关键字的属性特性，提出了相关关系、最大相关块等概念。讨论了有关定理，最后给出了求基数为Ｍ的候选关键字的多项式时间算法。

On the basis of [3],the features of the attributes composing a candidate key are discussed in detail and deeply,the concepts such as relative relation,maximal relative block,etc.are presented,and the relative theorems are also discussed. Finally,a polynomial-time algorithm to find the candidate key whose cardinality is M is given.