Institute for Informatics
Georg-August-Universität Göttingen

Databases and Information Systems

Uni Göttingen

Information Systems 33(6), pp. 508-566, 2008.

Integrating and Querying Distributed XML Data via XLink

Erik Behrends, Oliver Fritzen, Wolfgang May


XML instances are not necessarily self-contained but may have connections to remote XML data residing on other servers. In this paper, we show that -in spite of its minor support and use in the XML world- the XLink language provides a powerful mechanism for expressing such links both from the modeling point of view and for actually querying interlinked XML data: In our dbxlink approach, the links are not seen as explicit links (where the users must be aware of the links and traverse them explicitly in their queries), but define views that combine into a logical, transparent XML model which serves as an external schema and can be queried by XPath/XQuery. We motivate the underlying modeling and give a concise and declarative specification as an XML-to-XML mapping. We also describe the implementation of the model as an extension of the eXist XML database system. The approach can be applied both for distribution of data and for integration of data from autonomous sources.

This paper is an extended version of the 10th. Intl. Conference on Extending Database Technology (EDBT'06) and Query Languages and Query Processing (QLQP'06) papers.