Recently, user demands for integrated searches over different information sources have been increasing rapidly. However, it is not easy to seamlessly integrate distributed heterogeneous information retrieval systems. In particular, resolving the discrepancies in the structures and semantics in the databases that are to be integrated is one of the most challenging research issues. In this paper, we propose an iKRISTAL system that integrates distributed, heterogeneous information retrieval systems without requiring source code-level modifications of the participating systems. The key element of our approach to address the structural and semantic discrepancies is to make use of schema mapping and a standardized framework for metadata registry. We have implemented and deployed a prototype implementation that integrates six different information sources, each of which is built upon heterogeneous schemas. Furthermore, we evaluated the performance of our approach under various configurations.
Integrated information retrieval; Metadata registry; Schema mapping