Using Correspondence Assertions for Specifying the Semantics of XML-Based Mediators.
Vânia Maria Ponte Vidal, Bernadette Farias Lóscio, Ana Carolina Salgado · 2001
Abstract Mediators are facilities that support an integrated view over multiple information sources, and allow for queries to be made against the integrated view. To facilitate an uniform and flexible representation of arbitrary source data, there is an increasing interest in using XML for data exchange and integration. In XML-based integration systems, instance information is represented by XML documents and schema information is represented by XML DTD. In this work, we propose the use of correspondence assertions to formally specify the relationship between the mediator schema and the source databases schemas. In that way, the mediators correspondence assertions semantically specify how the mediator objects are synthesized from the sources’ objects. The advantage of our formalism is that it can manage the problem of semantic heterogeneity, the fact that mediator data is represented differently in the underlying information sources. In this paper we discuss how the semantic specification of mediators can be used to automate some aspects of data integration.