Efficient evaluation in XML to XML transformations

Different communities specify different standards (DTDs) and only those XML documents conforming to the given DTD can be processed inside a certain community. The goal of DTD-conforming XML to XML transformations with XML Transformation Grammars is to make exchanging XML documents between two communities whose DTDs are distinct feasible. However, in essence XTG evaluation is the process of executing a number of XML queries and thus this presents new challenges to query optimization. In this paper, we investigate each step of evaluating an XTG, and after modelling XML queries, we propose some optimization techniques to speed up XTG evaluation. Finally, the experimental results indicate that those techniques are efficient to XTG evaluation.