So9q added a comment.

  In T291903#7411375 <https://phabricator.wikimedia.org/T291903#7411375>, 
@Hannah_Bast wrote:
  
  >> Oh, ok. Could you give an example of a query that has no "highly selective 
triples" so I can test it on QLever vs. BG?
  >
  > Here is a relatively simple query without a highly selective triple. It 
asks for the 100 people with the most professions. It requires a JOIN of the 
first triple (around 9 million people) with the second triple (all people and 
their professions, around 8.5 million triples). And there is no easy way around 
computing the full join result because we want the people with the most 
professions in the end and you cannot know in advance which people these are. 
The query deliberately does not have a large query result. So if it takes long, 
it's not because the output is so large.
  >
  >   PREFIX wd: <http://www.wikidata.org/entity/>
  >   PREFIX wdt: <http://www.wikidata.org/prop/direct/>
  >   PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
  >   SELECT ?person ?name (COUNT(?profession) AS ?count) WHERE {
  >     ?person wdt:P31 wd:Q5 .
  >     ?person wdt:P106 ?profession .
  >     ?person rdfs:label ?name .
  >     FILTER (LANG(?name) = "en")
  >   }
  >   GROUP BY ?person ?name
  >   ORDER BY DESC(?count)
  >   LIMIT 100
  >
  > PS: Here you can see the performance on QLever: 
https://qlever.cs.uni-freiburg.de/wikidata/cYvT6w
  
  Thanks for the swift reply. Wow.
  F34680819: bild.png <https://phabricator.wikimedia.org/F34680819>
  BG is totally aced 😅 (times out, so 60+s vs. 1.97s)
  
  I'm feeling more and more motivated to get QLever up and running on 
Toolforge. Send my thanks to your team for writing this beautiful and fast 
engine and releasing it as open source software!

TASK DETAIL
  https://phabricator.wikimedia.org/T291903

EMAIL PREFERENCES
  https://phabricator.wikimedia.org/settings/panel/emailpreferences/

To: So9q
Cc: DD063520, Justin0x2004, Hannah_Bast, So9q, Aklapper, Invadibot, MPhamWMF, 
maantietaja, CBogen, Akuckartz, Nandana, Namenlos314, Lahi, Gq86, 
Lucas_Werkmeister_WMDE, GoranSMilovanovic, QZanden, EBjune, merbst, 
LawExplorer, _jensen, rosalieper, Scott_WUaS, Jonas, Xmlizer, jkroll, 
Wikidata-bugs, Jdouglas, aude, Tobias1984, Manybubbles, Mbch331
_______________________________________________
Wikidata-bugs mailing list -- [email protected]
To unsubscribe send an email to [email protected]

Reply via email to