Optimized Query Processing for Virtual and Distributed Xml Databases

Abstract

This paper examines the optimization convention for XQuery queries, which is basically used for querying XML documents, such queries exploit type information of the preimage XML document provided in the XML schema. The optimization convention discussed in this paper are widely applicable for nearly every type of the XQuery expression and is found to be extremely useful, specifically in the context of XQuery queries on XQuery views. The concept behind the work of this paper is transformation of the XML Schema definition into a graph, which is further extended to a graph displaying the XQuery expression. The later extended part of the graph is further utilized to delete the sub expressions of the XQuery expression that are found to be unused for reaching the final set of result. Further the experimental result of our work demonstrates the improvement of our optimization.

Keywords: indexing, labelling scheme, query optimization, XML storage.