【摘要】 文中通过对关系模式中的属性进行适当的分类，讨论了一个属性成为主属性应该满足的条件，并在文献［４］、［５］、［６］的基础上，采用闭包，实现了利用Ａｒｍｓｔｒｏｎｇ公理进行函数依赖推导的过程，从而给出了一个简便的求解关系模式全部主属性的多项式时间算法．更多还原

【Abstract】 The condition under which an attribute is a prime attribute is studied by classifying the attributes. The inference of functional dependencies based on Armstrong axiom is realized using the closure, and a polynomial time algorithm to find all prime attributes of a relation schema is given on the basis of the related references .更多还原