Time to Leave the Trees: From Syntactic to Conceptual Querying of XML

Current XML query languages operate on XML instances only but ignore valuable conceptual level information that is "buried" inside complex XML Schema documents. For example, XPath queries are evaluated against XML documents based on element names (tags) and their syntactic nesting structure, ignoring the element types and other conceptual level information that is declared in separate XML schemas. We propose an extension to XML query languages for conceptual querying of XML, based on an underlying abstract model of XML Schema (MXS). We show that this approach offers the user new and often more adequate high-level query capabilities beyond the traditional purely syntactic approach of querying XML trees.