Hello list, I have a SPARQL query file with the following structure:
PREFIX disq: <http://foo/bar#> SELECT ?id ?label ?term ?type WHERE { { ?id disq:preferredLabel ?label ; disq:hasSearchTerm ?term ; a ?type FILTER (?id in ( <id1>, <id2>, ..., <id4094> )) } UNION { ?id disq:preferredLabel ?label ; disq:hasSearchTerm ?term ; a ?type FILTER (?id in ( <id4095>, ..., <id6000> )) } } (so the first FILTER statement filters 4094 ID's, the second one filters from ID 4095 up to ID 6000. I'm running this query against the following version of Virtuoso: 'Version 07.10.3209-pthreads for Linux as of May 27 2014' using curl like this: curl --silent -S \ -w "%{time_total}\n" \ -H 'Accept: text/csv' \ -F "query=@myquery.rq" \ http://myserver:8890/sparql I was checking if the time it takes for the above query is quite constant, so therefore I repeat the curl command 1000 times and I look at the time that curl reports me. The resulting graph is online at https://plus.google.com/photos/108476541542561906992/albums/6054059571162128769?authkey=CJjRirrc7_6iQQ As one can see in the graph, most of the time, the query takes about 1 second to execute. However, at about each 100 query executions, the query takes somewhere between 3 and 7 seconds. I was wondering why I see this behaviour. Why does the query 'suddenly' take much more time than usual? Is this expected behaviour that is the result of Virtuoso internals? Could it be some other phenomenon that is more OS or network specific? If anybody has a (possible) explanation for this, or knows of extra (monitoring?) tests I can do to gain more insight, I would be glad to hear! Kind regards, Bart ------------------------------------------------------------------------------ Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ _______________________________________________ Virtuoso-users mailing list Virtuoso-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/virtuoso-users
