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Information sources registration at a subject mediator

Information sources registration at a subject mediator as compositional development.

Author(s): Briukhov D.O., Kalinichenko L.A., Skvortsov N.A.
Published:Advances in Databases and Information Systems: Proc. of the 5th East European Conference. LNCS 2151. -- Berlin-Heidelberg: Springer-Verlag, 2001. -- P. 70--83.
Method for heterogeneous information source registration at subject mediators with local as view (LAV) organization is presented. LAV approach considers schemas exported by sources as materialized views over virtual classes of the mediator. This approach is intended to cope with a dynamic, possibly incomplete set of sources. Sources may change their exported schemas, become unavailable from time to time. To disseminate the information sources, their providers should register them at a respective subject mediator. Such registration can be done concurrently and at any time. To make subject mediators scalable with respect to a number of sources involved, specific methods and tools supporting process of information sources registration are required. The registration method proposed is new and contributes to the following. The method is applicable to wide class of source specification models representable in hybrid semistructured/object canonical mediator model. Ontological specifications are used for identification of mediator classes semantically relevant to a source class. Maximal subset of source information relevant to the mediator classes is identified (due to identification of maximal commonality between a source and federated level class specification). Concretizing types are defined so that federated classes instance types are refined by the source instance type. This direction naturally supports query planning refining a mediator query in terms of a specific source. Such refining direction is in contrast to conventional compositional development where specification of requirements is to be refined by specifications of components. Such inversion is natural for the registration process: a materialized view (requirements) is constructed over virtual specifications (components). The method proposed is applicable not only to subject mediators, but also to data warehouse environment with the pre-defined conceptual (domain) model. In this case the method defines materialized views that can be used further to load them into the respective classes of the warehouse.
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