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  1. Blazegraph (by SYSTAP)
  2. BLZG-1048

bad performance for FILTER EXISTS

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    Details

    • Type: Bug
    • Status: Done
    • Resolution: Done
    • Affects Version/s: BIGDATA_RELEASE_1_3_1
    • Fix Version/s: None
    • Component/s: Other

      Description

      Using the 36 eg triples:

         eg:a eg:p eg:a, eg:b, eg:c, eg:d, eg:e, eg:f .
          eg:b eg:p eg:a, eg:b, eg:c, eg:d, eg:e, eg:f .
         eg:c eg:p eg:a, eg:b, eg:c, eg:d, eg:e, eg:f .
          eg:d eg:p eg:a, eg:b, eg:c, eg:d, eg:e, eg:f .
          eg:e eg:p eg:a, eg:b, eg:c, eg:d, eg:e, eg:f .
         eg:f eg:p eg:a, eg:b, eg:c, eg:d, eg:e, eg:f . 
      

      Ask either

      Prefix eg: <eg:>
      ASK
      FROM eg:g
      { BIND (1 as ?t)
        ?a eg:p/eg:p/eg:p/eg:p/eg:p/eg:p/eg:p/eg:p ?b
      }
      
      

      or

      Prefix eg: <eg:>
      SELET *
      FROM eg:g
      { BIND (1 as ?t)
        FILTER EXISTS {
          ?a eg:p/eg:p/eg:p/eg:p/eg:p/eg:p/eg:p/eg:p ?b
       }
      }
      

      The former takes less than 10 ms, the latter more than 5s.
      This suggests that the execution of FILTER EXISTS is not terminating when the first solution is found.

      See BLZG-1049 (Query hint not recognized in FILTER) for a related issue.

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            Assignee:
            bryanthompson bryanthompson
            Reporter:
            jeremycarroll jeremycarroll
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              Created:
              Updated:
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