Rough Set Based Algorithm of Discovering Functional Dependency for XML
一个基于粗糙集的XML函数依赖发现算法

Data dependency is an important concept in database research.Functional Dependency plays a fundamental role in data dependency where it provides semantics for the data.Since XML recently appear largely,XFD is introduced into XML research.On the basis of the range of constraints,XFD is redefined in XML.And we propose one algorithm that discovering minimal XFD,based on the rough set handling non-integrity data.It is based on the concept of agree sets,and the computation of agree sets can be decreased by using stripped partition tuples on indiscernibility relation.A levelwise algorithm is used for computing the left hand sides(lhs)of minimal non-trivial functional dependency.The semantics information is important to the design of XML schema,query optimization and check of update abnormity.