Information Integration through Reasoning on Meta-data

SILK is an Enterprise Information Integration (EII) system using knowledge representation and reasoning techniques to support both mediation and integration of heterogeneous information sources. The SILK system is built around a Model Warehouse which stores models of single information sources, as well as unified models and their customised abstractions. Models include constraints describing non-structural properties of the data sources. In the process of integration, the Model Warehouse is extended with mappings, which link the models, and spell out their relationship using appropriate constraints. The paper describes several components of the SILK tool-set. The Rule Compiler is responsible for transforming the constraints to a format suitable for mediation. The Comparator tool uses structural and textual comparison techniques to pinpoint related elements of the models and to help in building the mappings. The Verifier component contains multiple reasoning modules coordinated by a central scheduler, which help in the process of integration by detecting inconsistencies in the models and the mappings. The RDF-wrapper, a recent extension of SILK, not only gives access to information available in RDF format, but also includes its own reasoning and consistency checking capabilities. Finally, we also discuss a planned extension of the SILK, focusing on information integration in an agent-based mobile computing environment.