On 10/9/24 2:57 PM, Kingsley Idehen via Wikidata wrote:

On 10/9/24 2:41 PM, Kingsley Idehen via Wikidata wrote:

Hi Peter,

On 10/9/24 2:26 PM, Peter F. Patel-Schneider wrote:

I use the QLever Wikidata SPARQL service at https://qlever.cs.uni-freiburg.de/wikidata/ The Virtuoso service I use is at https://wikidata.demo.openlinksw.com/sparql I believe that both of these are the standard endpoints and are the same that you used.

peter

For this kind of transitive closure Virtuoso needs a starting point.

https://wikidata.demo.openlinksw.com/sparql?default-graph-uri=http%3A%2F%2Fwww.wikidata.org%2F&query=SELECT+%3Fsub+%3Fsuper+WHERE+%7B%0D%0A++%3Fsub+wdt%3AP279%2B+%3Fsuper+.%0D%0A+++FILTER+%28%3Fsub+%3D+%3Chttp%3A%2F%2Fwww.wikidata.org%2Fentity%2FQ391414%3E%29%0D%0A%7D+%0D%0A&format=text%2Fhtml&timeout=30000&signal_void=on

Can you not share a similar SPARQL Protocol link for QLever?

Kingsley

Another variant.

https://wikidata.demo.openlinksw.com/sparql?default-graph-uri=http%3A%2F%2Fwww.wikidata.org%2F&query=SELECT+%3Fsub+%3Fsuper+WHERE+%7B%0D%0A++%3Fsub+wdt%3AP279%2B+%3Fsuper+.%0D%0A+FILTER%28+%3Fsuper+%3D+%3Chttp%3A%2F%2Fwww.wikidata.org%2Fentity%2FQ385378%3E%29%0D%0A%7D+&format=text%2Fx-html%2Btr&timeout=30000&signal_void=on

Query text.


SELECT ?sub ?super WHERE {
?sub wdt:P279+ ?super .
FILTER( ?super = <http://www.wikidata.org/entity/Q385378>)
}

Okay, here’s a QLever query that handles the transitive closure with a constant designating a start point.

https://qlever.cs.uni-freiburg.de/wikidata/?query=PREFIX+wdt%3A+%3Chttp%3A%2F%2Fwww.wikidata.org%2Fprop%2Fdirect%2F%3E%0ASELECT+%3Fsub+%3Fsuper+WHERE+%7B%0A++%3Fsub+wdt%3AP279%2B+%3Fsuper+.%0A+%23+FILTER%28+%3Fsuper+%3D+%3Chttp%3A%2F%2Fwww.wikidata.org%2Fentity%2FQ385378%3E%29%0A%7D+

We’ll take a look at how that’s being pull off since the following fails, stating:

“Error processing query

Tried to allocate 30 GB, but only 9.9 GB were available. Clear the cache or allow more memory for QLever during startup”

https://qlever.cs.uni-freiburg.de/wikidata/?query=SELECT+%28SAMPLE%28%3Fs%29+as+%3Fsample%29+%28count%28%2A%29+as+%3Fcount%29+%3Fo+%0AWHERE+%7B%3Fs+a+%3Fo%7D+%0AGROUP+BY+%3Fo+%0AORDER+BY+DESC+%28%3Fcount%29+%0ALIMIT+20+


SELECT (SAMPLE(?s) as ?sample) (count(*) as ?count) ?o 
WHERE {?s a ?o} 
GROUP BY ?o 
ORDER BY DESC (?count) 
LIMIT 20 

-- 
Regards,

Kingsley Idehen	      
Founder & CEO 
OpenLink Software   
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