Functional Dependencies for XML
نویسندگان
چکیده
In this paper we address the problem of how to extend the deenition of functional dependencies (FDs) in incomplete relations to XML documents. An incomplete relation is said to strongly satisfy a FD if every completion of the relation, obtained by replacing all null values by data values, satisses the FD in the ordinary sense. We propose a syntactic deenition of strong FD satisfaction in a XML document (called a XFD) and then justify it by proving that for a very general class of mappings of a relation into a XML document, a relation strongly satisses a unary FD if and only if the XML document also strongly satisses the equivalent XFD.
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