Fuseki with in-memory backend or TDB?

Which version?

How large is the dataset? Not that I see how this simple query with a single join should lead to a timeout, but any numbers are usually helpful.

Did you try the query without defining the default graph but using a graph pattern, i.e.

SELECT *
WHERE {
  GRAPH <https://a.b.c> {<https://x.y.z> a ?t .
  ?t skos:prefLabel ?l }
}


And/or did you try to reorder the triple patterns? The query optimizer should prefer the first one though anyways as it can make use of spo index (if it would be TDB)

On 15.09.22 11:16, Mikael Pesonen wrote:

This returns one row fast, say :C1

SELECT *
FROM <https://a.b.c>
WHERE {
  <https://x.y.z> a ?t .
  #?t skos:prefLabel ?l
}


and this too:

SELECT *
FROM <https://a.b.c>
WHERE {
  #<https://x.y.z> a ?t .
  :C1 skos:prefLabel ?l
}


But this always hangs until timeout

SELECT *
FROM <https://a.b.c>
WHERE {
  <https://x.y.z> a ?t .
  ?t skos:prefLabel ?l
}

What am I missing here? I'm using Fuseki web GUI. Thanks!

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