TGV: a Tree Graph View for Modelling untyped XQuery

International audienceTree Pattern Queries[sihem2002,jagadish2001] are now well admitted for modeling parts of XML Queries. Actual works only focus on a small subpart of XQuery specifications and are not well adapted for evaluation in a distributed heterogeneous environment. In this paper, we propose the TGV (Tree Graph View) model for XQuery processing. The TGV model extends the Tree Pattern representation in order to make it intuitive, has support for full untyped-XQuery queries, and for optimization and evaluation. Several types of Tree Pattern are manipulated to handle all XQuery requirements. Links between Tree Patterns are called hyperlinks in order to apply transformations on results. The TGV has been implemented in a mediator system called XLive