TwigX-Guide: Twig Query Pattern Matching for XML Trees

The growing importance of XML and the lack of efficient solutions for managing and querying XML data have led to the development of hybrid systems. We present a hybrid system, TwigX-Guide; an extension of the well-known DataGuide index and region encoding labeling to support twig query processing. With TwigX-Guide, a complex query can be decomposed into a set of path queries, which are evaluated individually by retrieving the path or node matches from the DataGuide index table and subsequently joining the results using the holistic twig join algorithm TwigStack. TwigX-Guide improves the performance of TwigStack for queries with parent-child relationships and mixed relationships by reducing the number of joins needed to evaluate a query. Experimental results indicate that TwigX-Guide can process path and twig queries on an average 38% better than the TwigStack algorithm, 29% better than TwigINLAB and 11% better than TwigStackList in terms of execution time.