http://docs.openlinksw.com/virtuoso/rdfandsparql.html OpenLink Virtuoso Universal Server: Documentation virtuoso.docs@openlinksw.com Mon, 16 Nov 2009 14:26:59 GMT OpenLink Software Documentation Team webmaster@openlinksw.com http://docs.openlinksw.com/virtuoso/../images/misc/logo.jpg http://docs.openlinksw.com/virtuoso/rdfandsparql.html OpenLink Virtuoso Universal Server: Documentation http://docs.openlinksw.com/virtuoso/rdfdatarepresentation.html virtuoso.docs@openlinksw.com Data Representation http://docs.openlinksw.com/virtuoso/rdfdatarepresentation.html Mon, 16 Nov 2009 14:26:59 GMT This section covers how Virtuoso stores RDF triples. The IRI_ID built-in data type is introduced, along with the default table structures used for triple persistency. These details are mostly hidden from users of RDF, thus this section is not necessary reading for typical use of Virtuoso with RDF. http://docs.openlinksw.com/virtuoso/rdfsparql.html virtuoso.docs@openlinksw.com SPARQL http://docs.openlinksw.com/virtuoso/rdfsparql.html Mon, 16 Nov 2009 14:26:59 GMT http://docs.openlinksw.com/virtuoso/rdfgraphsecurity.html virtuoso.docs@openlinksw.com RDF Graphs Security http://docs.openlinksw.com/virtuoso/rdfgraphsecurity.html Mon, 16 Nov 2009 14:26:59 GMT http://docs.openlinksw.com/virtuoso/rdfrdfviewgnr.html virtuoso.docs@openlinksw.com Automated Generation of RDF Views over Relational Data Sources http://docs.openlinksw.com/virtuoso/rdfrdfviewgnr.html Mon, 16 Nov 2009 14:26:59 GMT http://docs.openlinksw.com/virtuoso/rdfinsertmethods.html virtuoso.docs@openlinksw.com RDF Insert Methods in Virtuoso http://docs.openlinksw.com/virtuoso/rdfinsertmethods.html Mon, 16 Nov 2009 14:26:59 GMT http://docs.openlinksw.com/virtuoso/rdfsparqlintegrationmiddleware.html virtuoso.docs@openlinksw.com Integration Middleware http://docs.openlinksw.com/virtuoso/rdfsparqlintegrationmiddleware.html Mon, 16 Nov 2009 14:26:59 GMT http://docs.openlinksw.com/virtuoso/rdfiridereferencing.html virtuoso.docs@openlinksw.com Linked Data http://docs.openlinksw.com/virtuoso/rdfiridereferencing.html Mon, 16 Nov 2009 14:26:59 GMT There are many cases when RDF data should be retrieved from remote sources only when really needed. E.g., a scheduling application may read personal calendars from personal sites of its users. Calendar data expire quickly, so there's no reason to frequently re-load them in hope that they are queried before expired. Virtuoso extends SPARQL so it is possible to download RDF resource from a given IRI, parse them and store the resulting triples in a graph, all three operations will be performed during the SPARQL query execution. The IRI of graph to store triples is usually equal to the IRI where the resource is download from, so the feature is named "IRI dereferencing" There are two different use cases for this feature. In simple case, a SPARQL query contains from clauses that enumerate graphs to process, but there are no triples in DB.DBA.RDF_QUAD that correspond to some of these graphs. The query execution starts with dereferencing of these graphs and the rest runs as usual. In more sophisticated case, the query is executed many times in a loop. Every execution produces a partial result. SPARQL processor checks for IRIs in the result such that resources with that IRIs may contain relevant data but not yet loaded into the DB.DBA.RDF_QUAD. After some iteration, the partial result is identical to the result of the previous iteration, because there's no more data to retrieve. As the last step, SPARQL processor builds the final result set. http://docs.openlinksw.com/virtuoso/rdfsparqlrule.html virtuoso.docs@openlinksw.com Inference Rules & Reasoning http://docs.openlinksw.com/virtuoso/rdfsparqlrule.html Mon, 16 Nov 2009 14:26:59 GMT http://docs.openlinksw.com/virtuoso/rdfperformancetuning.html virtuoso.docs@openlinksw.com Performance Tuning http://docs.openlinksw.com/virtuoso/rdfperformancetuning.html Mon, 16 Nov 2009 14:26:59 GMT For RDF query performance, we have the following possible questions: http://docs.openlinksw.com/virtuoso/rdfnativestorageproviders.html virtuoso.docs@openlinksw.com RDF Data Access Providers (Drivers) http://docs.openlinksw.com/virtuoso/rdfnativestorageproviders.html Mon, 16 Nov 2009 14:26:59 GMT