La reécriture et l’évaluation de requêtes arbres avec XPath Rewriting and Evaluating Tree Queries with XPath

A Community Web portal is a set of tools for a community of people who want to share information on a certain domain via the Web. The backbone of this system is an ontology which is understood by all members of the community and used as the common interface component for integrating, querying, structuring and exchanging information. This paper describes a simple but nevertheless powerful language for integrating XML documents into a Community Web system. More precisely, we describe how to add and exploit XPath enabled Web servers by mapping standard XPath location paths to conceptual paths in the system ontology. We present a query rewriting algorithm using such mappings. It transforms a user query into a set of XML queries based on XPath patterns for selecting XML fragments. Finally, we describe some evaluation techniques for reducing the size of XML data returned by the XML source for query evaluation.