Hi Paolo,
thanks for your reply. I've already tried your rewritten query, but it
does not terminate, too. I really do not know why is that - hopefully
someone can give me a useful hint!
Thorben
Am 24.10.2011 18:51, schrieb Paolo Castagna:
Hi Thorben
I am sorry, I do not have the answer to your question.
I have a question and a couple of comments I wanted to share with you.
Thorben Wallmeyer wrote:
Am 24.10.2011 18:11, schrieb Thorben Wallmeyer:
Hi,
I've got an OntModel with OnModelSpec.OWL_MEM_RULE_INF set that
contains about 25.000 statements and only 1(!) transitive property.
Now I'm trying to list all Statements with a special subject
(http://myResource) by calling
StmtIterator iter =
model.listStatements(model.createResource("http://myResource";),
null, (RDFNode) null);
Although execution of this method does not take a long time (some
seconds) I run in serious trouble/performance issue when calling
iter.hasNext();
This call does not terminate within 5 minutes and I'm asking myself
if what's wrong. Therefore I'm looking for better solution and your
suggestions... ;-)
Best,
Thorben
Some problem with:
String query = "SELECT ?s ?p ?o WHERE {?s ?p ?o. FILTER(?s
=<METEX://knowledge/infection> ).}";
QueryExecution qexec= QueryExecutionFactory.create(query,
tmpModel);
ResultSet rs = qexec.execSelect();
Are you running this query over the same OntModel?
This is also an equivalent query:
SELECT * WHERE { <METEX://knowledge/infection> ?p ?o . }
But, if you are using the same OntModel, I do not expect
is going to make any difference.
Is there a way or need to explicitly define a customized index?
Interesting question... :-)
An example of this is LARQ = Lucene + ARQ.
LARQ uses Lucene (i.e. a separate index) to answer free text queries.
Documentation is here:
http://incubator.apache.org/jena/documentation/larq/
Sources are here:
http://svn.apache.org/repos/asf/incubator/jena/Jena2/LARQ/trunk/
But, I would not rush to try doing something better with a customized
index, before understand what's going on and why your initial attempt
is slow.
Another option you might look at is:
http://openjena.org/wiki/RIOT#Inference
Paolo
Thorben
