Inclusion Dependencies in XML: Extending Relational Semantics

In this article we define a new type of integrity constraint in XML, called an XML inclusion constraint (XIND), and show that it extends the semantics of a relational inclusion dependency. This property is important in areas such as XML publishing and `data-centric' XML, and is one that is not possessed by other proposals for XML inclusion constraints. We also investigate the implication and consistency problems for XINDs in complete XML documents, a class of XML documents that generalizes the notion of a complete relation, and present an axiom system that we show to be sound and complete.