Finally on Chrome: 320 results in 3496.4s in my settings.
I got the same result on Chrome, but it took 4600 sec here (1h 20min).
Definitely a case of the query planner making a very wrong decision here. These are interesting examples we need to check when designing the new query engine.
For this particular query, I can imagine the star shape to be problematic for the query algorithm. Probably, the best choice here is to: – first evaluate ?named wdt:P21 wd:Q6581072 – then evaluate ?street wdt:P138 ?named . – then download all data of ?street However, the current engine will go through all 5 patterns in a chain. Other work looked at better algorithms (http://linkeddatafragments.org/publications/#query-algorithm-optimizations), but these still need to be added to the public engine.
Thanks for the feedback, this has been very interesting already. It's curious such examples never came up with DBpedia in the two years we had the fragments endpoint up. I wonder whether that's due to the Wikidata community's enthusiasm or due to the different shape of the data.
Cheers,
Ruben