Tree-pattern queries on a lightweight XML processor

Abstract

Popular XML languages, like XPath, use "treepattern " queries to select nodes based on their structural characteristics. While many processing methods have already been proposed for such queries, none of them has found its way to any of the existing "lightweight" XML engines (i.e. engines without optimization modules). The main reason is the lack of a systematic comparison of query methods under a common storage model. In this work, we aim to fill this gap and answer two important questions: what the relative similarities and important differences among the tree-pattern query methods are, and if there is a prominent method among them in terms of effectiveness and robustness that an XML processor should support.