Hi, Michael --
On Jul 6, 2009, at 06:49 AM, Michael Haas wrote:
> Michael Haas wrote:
>> It looks like the public sparql endpoint at http://dbpedia.org/
>> sparql is now limiting the result set. This always used to be true
>> for the web interface, but using the ARQ libs, I always got the
>> full result set. I last tried this about two weeks ago. Today, I
>> get way less results.
>
> After lots of confusion during the weekend which finally cleared up,
> I'm still a bit unsure if this issue is resolved or not.
>
> When listing all actors, I'm still not getting as many results as
> two weeks ago - it still stops after Dominic Purcel for my Actors
> query. [0]
>
> Has the issue regarding the misconfiguration of the cluster node
> been resolved? If so, is this the intended behavior now?
>
> Note that I'm not complaining or implying something is broken, I'm
> mainly curious if this is intended behaviour or not.
>
> ...
>
> [0] SELECT ?name WHERE { ?a <http://www.w3.org/1999/02/22-rdf-syntax-ns#type
> > <http://dbpedia.org/ontology/Actor> . ?a
> > <http://www.w3.org/2000/01/rdf-schema#label
> > ?name }
As Kingsley indicated, this is intended behavior, which should (and
will, if it isn't already) be noted on relevant DBpedia project pages,
as well as through the various interfaces as they permit.
You can analyze the results you're getting to see that the current
limit is 1000 rows per result set. You can work through this by
adding ORDER BY and LIMIT/OFFSET clauses to your query, and stepping
through the subsets --
SELECT ?name
WHERE
{
?a <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://dbpedia.org/ontology/Actor> .
?a <http://www.w3.org/2000/01/rdf-schema#label>
?name
}
ORDER BY ?name
LIMIT 1000
OFFSET 1000 <-- 2000,3000,4000,...
You may wish to set the offset at multiples of 999, to get a single-row
overlap between sets, which can then be used as a sanity check.
Note that the ORDER BY is *required* or you cannot be sure that the
results returned are coming in the same order every time, and thus
you cannot be sure that the OFFSET is skipping only already-returned
rows. (Just as with SQL...)
Regards,
Ted
--
A: Yes. http://www.guckes.net/faq/attribution.html
| Q: Are you sure?
| | A: Because it reverses the logical flow of conversation.
| | | Q: Why is top posting frowned upon?
Ted Thibodeau, Jr. // voice +1-781-273-0900 x32
Evangelism & Support // mailto:[email protected]
OpenLink Software, Inc. // http://www.openlinksw.com/
http://www.openlinksw.com/weblogs/uda/
OpenLink Blogs http://www.openlinksw.com/weblogs/virtuoso/
http://www.openlinksw.com/blog/~kidehen/
Universal Data Access and Virtual Database Technology Providers
------------------------------------------------------------------------------
_______________________________________________
Dbpedia-discussion mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion
