A new sequence-based approach for XML data query

Abstract

In order to avoid expensive join operations in query processing from structured XML document, some index methods based on sequence have been proposed, which transform XML documents and twig patterns into sequences. By performing subsequence matching, query is processed holistically without breaking the twig pattern into many individual root-to-leaf paths, and large useless intermediate results and expensive join operations are avoided. In this paper, combining path sequence strategy with region labeling scheme, we propose a new sequence scheme, Region Path sequence scheme, where the last node of each path is labeled with the region labeling scheme. Compared with previous approaches, our approach can avoid false alarm more effectively, and any extra structure for labeling needn't be constructed. Furthermore, we construct two level B+-tree structure to finish the matching, and also propose corresponding matching algorithm. Experiment results demonstrate that our approach can not only avoid false alarm, but also process query more quickly than previous methods such as ViST, and Constraint Sequence. © 2013 Springer-Verlag.