Processing XPath queries with XML summaries

Range labeling and structural joins are well-studied techniques for efficiently processing XPath queries. However, when XPath queries become long, many times of structural joins are required. To solve this problem, we developed a method to reduce the number of joins and nodes read from the disk using strong DataGuides. Our method can process single paths without any joins and twig patterns with joins amongst branching nodes and leaves in queries. Experimental results verified that our approach outperforms the best optimization technique for structural joins by factors of up to several hundreds of times.