Uploaded image for project: 'Blazegraph (by SYSTAP)'
  1. Blazegraph (by SYSTAP)
  2. BLZG-4604

Query does not perform after eliminating subselect

    XMLWordPrintable

    Details

    • Type: Bug
    • Status: Open
    • Priority: Medium
    • Resolution: Unresolved
    • Affects Version/s: BLAZEGRAPH_2_1_4
    • Fix Version/s: None
    • Component/s: Wikidata Query Service
    • Labels:
      None

      Description

      This query:

      SELECT DISTINCT ?id ?label ?description WHERE {
        {
          SELECT ?id WHERE { ?i wdt:P31 ?id. }
        }
        ?id rdfs:label ?label.
        ?id schema:description ?description.
        FILTER((LANG(?label)) = "en")
        FILTER((LANG(?description)) = "en")
      }
      LIMIT 20
      

      performs fine, but after eliminating subselect:

      SELECT DISTINCT ?id ?label ?description WHERE {
        ?i wdt:P31 ?id. 
        ?id rdfs:label ?label.
        ?id schema:description ?description.
        FILTER((LANG(?label)) = "en")
        FILTER((LANG(?description)) = "en")
      }
      LIMIT 20
      

      The same query does not perform and times out. Looks like optimizer is not doing the right thing here, though disabling optimizer does not help too.

        Attachments

          Activity

            People

            Assignee:
            bryanthompson bryanthompson
            Reporter:
            stasmalyshev stasmalyshev
            Votes:
            0 Vote for this issue
            Watchers:
            4 Start watching this issue

              Dates

              Created:
              Updated: