RDFSculpt: Managing RDF schemas under set-like semantics

Abstract

The Semantic Web is an extension of the current Web in which information is given well-defined meaning to support effective data discovery and integration. The RDF framework is a key issue for the Semantic Web. It can be used in resource discovery to provide better search engine capabilities, in cataloging for describing the content of thematic hierarchies in thematic catalogs and digital libraries, in knowledge sharing and exchange of Web agents, etc. Up to now, RDF schemas have been treated rather as sets of individual elements (i.e. model primitives like classes, properties, etc.). Under that view, queries like "find the part of a portal catalog which is not present in another catalog" can be answered only in a procedural way, specifying which nodes to select and how to get them. For this reason, we argue that answering such queries requires treating schemas as a whole rather than as sets of individual elements. We introduce a set of operators with set-like semantics to manage RDF schemas. The operators can be included in any RDF query language to support manipulation of RDF schemas as full-fledged objects. We also present RDFSculpt, a prototype system that implements our framework. © Springer-Verlag Berlin Heidelberg 2005.