Hierarchical Stack-Based Twig Query Algorithm of XML Data

Nowadays, many researchers focus on twig query pattern of XML data. The main representatives are the Holistic Twig Joins method, the use of XR-Tree Index based on it, or the algorithm of identifying directly XML nodes satisfying consecutive parent-children edge-path. All of these efforts don´t improve the efficiency of twig query at all. In this paper, several common twig query algorithms of XML data were analyzed firstly. Then a new coding called EDiezt-P, which is highly flexible and easy to determine the structure relationship of node pairs, is proposed. Based on the EDiezt-P coding and hierarchical stack structure, a new bottom-up Twig query algorithm-TwigStack-HST was proposed. The results of Experiments showed that the query processing time was shortened and the query efficiency was improved by the new TwigStack-HST algorithm.