Hi All I loaded DBPedia RDF dump File to JenaTDB store. The triples were loaded successively including the indexingphase and “stats,opt” file was created; however, the SPARQL queries are notworking for complex queries. It takes very long time (and non-stop runningsometimes). I ran “tdbstats” command to optimize TDB but there was no change tothe query running or to “stats.opt”. The “tdbstats” command does not create anyOptimizer control file.After I removed the “stats.opt” fileand ran the query, I got a result even after a very long time. I tried those opertions in two kind of computers. The first is with Windows7-x64,Intel i7 4 cores, 32GB RAM. 2TB HD. The second is with OS X 10.10.2, Intel i7,16GB RAM, 1TB HD.************************************************************** The query that I am using to test is:******************************************************************* PREFIX rdfs:<http://www.w3.org/2000/01/rdf-schema#>PREFIX dbpo: <http://dbpedia.org/ontology/>PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>SELECT DISTINCT ?lblWHERE { { ?entity1 ?rel ?entity2 } UNION { ?entity2 ?rel ?entity1 } ?entity1 rdf:type dbpo:Person . ?entity2 rdf:type dbpo:Place . ?rel rdfs:label ?lbl FILTER ( lang(?lbl) = "en" )} ******************************************************************** the JAVA code to run query is:************************************************************************ Location location = new Location("C:/myFiles/RDF-DBPedia/TDB-DP") ; Dataset dataset = TDBFactory.createDataset(location); dataset.begin(ReadWrite.READ) ; try{ QueryExecution ex = QueryExecutionFactory.create(query, dataset); ResultSet res = ex.execSelect() ; ResultSetFormatter.out(res) ; } finally { dataset.end() ; } ******************************************************************
The total time taken in Windows was: 20 minutes 34seconds.The total time taken in MAC was: 26 minutes 58seconds.The total time taken in online DBPedia endpoint was seconds.My question is: what kind of instructions or stepsI miss to get query results in a local TDB storage faster? Thanks in advanceAbdul
