Hello Mirko, What indexes do you have? You may need at least bitmap SPOG index for the first query. The default layout (only two indexes) works for queries taht have all graphs fixed (or calculated before use), but not for all other queries.
Best Regards, Ivan Mikhailov OpenLink Software http://virtuoso.openlinksw.com On Fri, 2009-11-20 at 10:30 +0100, Mirko wrote: > Hi, > I have a SPARQL query which performes well when querying a single graph but > "the estimated execution time exceeds the time limit of 400 (secs)" when > querying two graphs. This is also true if the second graph is empty. Why is > this the case / how can I fix this? > > Query A (performes well): > > SELECT ?description FROM <http://localhost/graphA> WHERE { ?recource > <http://purl.org/dc/terms/subject> <http://localhost/someElement> . > ?recource <http://purl.org/dc/terms/subject> ?relatedElement . > ?relatedElement <http://purl.org/dc/terms/description> ?description . > ?relatedElement <http://localhost/score> ?score } ORDER BY DESC (?score) > LIMIT 4 > > query B (times out): > > SELECT ?description FROM <http://localhost/graphA> FROM > <http://localhost/graphB> WHERE { ?recource > <http://purl.org/dc/terms/subject> <http://localhost/someElement> . > ?recource <http://purl.org/dc/terms/subject> ?relatedElement . > ?relatedElement <http://purl.org/dc/terms/description> ?description . > ?relatedElement <http://localhost/score> ?score } ORDER BY DESC (?score) > LIMIT 4 > > -->"The estimated execution time 664 (sec) exceeds the limit of 400 (sec)." > > Regards, > -Mirko > ------------------------------------------------------------------------------ > Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day > trial. Simplify your report design, integration and deployment - and focus on > what you do best, core application coding. Discover what's new with > Crystal Reports now. http://p.sf.net/sfu/bobj-july > _______________________________________________ > Virtuoso-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/virtuoso-users
