a copy of the actual query + assertions would be advisable here in addition
to runtime information (cpu,mem,os,jdk)
On Sun 23. Feb 2020 at 18:57, Steve Vestal <steve.ves...@adventiumlabs.com>
wrote:
> I'm looking for suggestions on a SPARQL performance issue. My test
> model has ~800 sentences, and processing of one select query takes about
> 25 minutes. The query is a basic graph pattern with 9 variables and 20
> triples, plus a filter that forces distinct variables to have distinct
> solutions using pair-wise not-equals constraints. No option clause or
> anything else fancy.
>
> I am issuing the query against an inference model. Most of the asserted
> sentences are in imported models. If I iterate over all the statements
> in the OntModel, I get ~1500 almost instantly. I experimented with
> several of the reasoners.
>
> Below is the basic control flow. The thing I found curious is that the
> execSelect() method finishes almost instantly. It is the iteration over
> the ResultSet that is taking all the time, it seems in the call to
> selectResult.hasNext(). The result has 192 rows, 9 columns. The results
> are provided in bursts of 8 rows each, with ~1 minute between bursts.
>
> OntModel ontologyModel = getMyOntModel(); // Tried various
> reasoners
> String selectQuery = getMySelectQuery();
> QueryExecution selectExec =
> QueryExecutionFactory.create(selectQuery, ontologyModel);
> ResultSet selectResult = selectExec.execSelect();
> while (selectResult.hasNext()) { // Time seems to be spent in
> hasNext
> QuerySolution selectSolution = selectResult.next();
> for (String var : getMyVariablesOfInterest() {
> RDFNode varValue = selectSolution.get(var);
> // process varValue
> }
> }
>
> Any suggestions would be appreciated.
>
> --
---
Marco Neumann
KONA
