Hello Sebastian,
The very next VOS release will contain special optimization for
sparql select distinct ?g where { graph ?g { ?s ?p ?o }}
Meanwhile you may use an built-in SQL procedure
DB.DBA.SPARQL_SELECT_KNOWN_GRAPHS() that produce such a list. In next
release, a variant of that procedure will be used in the compilation of
the above mentioned query.
Best Regards,
Ivan Mikhailov
OpenLink Software
http://virtuoso.openlinksw.com
On Fri, 2009-11-20 at 15:27 +0100, Sebastian Hellmann wrote:
> Hello,
> what is the fastest way to query for a list of graphs in the store
> for the V5 and V6 series. I do not succeed to write a query that is
> faster than 10 seconds.
>
> I'm testing it on http://db0.aksw.org:8890/sparql , the latest VOS 6 ,
> which has DBpedia loaded and some OntoWiki graphs.
>
> I even tried this:
>
> SELECT DISTINCT ?graph WHERE { GRAPH ?graph {?s rdf:type ?o}}
>
> and it still needs almost 10 seconds, even if I call it very often,
> hoping for the cache to kick in ...
>
> Also a SQL query would be fine, but it needs to be fast
> (it should be fast normally < 20ms )
> It's for OntoWiki, so we also need a fast solution for the V5 series,
> to be backward compatible.
>
> Regards,
> Sebastian
>
> Expected result:
>
> graph
> http://www.openlinksw.com/schemas/virtrdf#
> http://www.w3.org/2002/07/owl#
> http://ns.ontowiki.net/SysOnt/
> http://dbpedia.org
> http://localhost/OntoWiki/Config/
>
>
