- From: Greg Karvounarakis <gregkar@csi.forth.gr>
- Date: Fri, 25 Feb 2000 17:34:21 +0200 (EET)
- To: www-rdf-interest@w3.org
As a part of our work on RDF, we have produced a technical report on querying RDF Metadata and Schemas. You can reach it online (in PDF format) at: http://www.ics.forth.gr/proj/isst/RDF/rdfquerying.pdf A short abstract follows: The need for descriptive information, i.e. metadata, about Web resources has been recognized in several application contexts (e.g., digital libraries, infomediaries, portals, etc.). The Resource Description Framework (RDF) aims at facilitating metadata creation and exchange. In particular, the definition of schema vocabularies enables the interpretation of RDF descriptions across several communities. Unfortunately, existing RDF-enabled systems (e.g. browsers, search engines) totally ignore schemas for metadata manipulation. In this paper, we propose RQL, a declarative language suitable for querying both RDF descriptions and schemas. RQL relies on a graph data model capturing the RDF modeling primitives in terms of classes and relationship types, organized into subsumption taxonomies. Furthermore, a graph instantiation mechanism is introduced to interpret semistructured RDF data using schema information. Taxonomies of labels are then exploited transparently in order to facilitate querying of complex semistructured data as well as of the schema vocabularies themselves. To the best of our knowledge RQL is the first language offering this functionality. Greg Karvounarakis ICS-FORTH, Greece
Received on Friday, 25 February 2000 10:41:24 UTC