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Posted to dev@jena.apache.org by "Andy Seaborne (JIRA)" <ji...@apache.org> on 2013/12/24 17:37:52 UTC

[jira] [Updated] (JENA-432) Filter optimization messes up when a nested select is present in the same block

     [ https://issues.apache.org/jira/browse/JENA-432?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Andy Seaborne updated JENA-432:
-------------------------------

    Description: 
The following test query:

{noformat}
SELECT ?test ?s1
WHERE {
  ?test ?p1 ?o1.
  FILTER ( ?test = <http://localhost/t1> || ?test = <http://localhost/t2> )  
  OPTIONAL {
    SELECT ?s1
    { ?s1 ?p2 ?o2 }
  }
}
{noformat}

produces the following plan:
{noformat}
(project (?test ?s1)
  (disjunction
    (table empty)
    (table empty)))
{noformat}

Something goes wrong with the FILTER expansion. As a workaround, we observed that the following variation:
{noformat}
SELECT ?test ?s1
WHERE {
  { ?test ?p1 ?o1.
    FILTER ( ?test = <http://localhost/t1> || ?test = <http://localhost/t2> )  
  }
  OPTIONAL {
    SELECT ?s1
    { ?s1 ?p2 ?o2 }
  }
}
{noformat}

produces the correct plan:
{noformat}
(project (?test ?s1)
  (leftjoin
    (disjunction
      (assign ((?test <http://localhost/t1>))
        (bgp (triple <http://localhost/t1> ?p1 ?o1)))
      (assign ((?test <http://localhost/t2>))
        (bgp (triple <http://localhost/t2> ?p1 ?o1))))
    (project (?s1)
      (bgp (triple ?s1 ?/p2 ?/o2)))))
{noformat}


  was:
The following test query:

SELECT ?test ?s1
WHERE {
  ?test ?p1 ?o1.
  FILTER ( ?test = <http://localhost/t1> || ?test = <http://localhost/t2> )  
  OPTIONAL {
    SELECT ?s1
    { ?s1 ?p2 ?o2 }
  }
}

produces the following plan:

(project (?test ?s1)
  (disjunction
    (table empty)
    (table empty)))

Something goes wrong with the FILTER expansion. As a workaround, we observed that the following variation:

SELECT ?test ?s1
WHERE {
  { ?test ?p1 ?o1.
    FILTER ( ?test = <http://localhost/t1> || ?test = <http://localhost/t2> )  
  }
  OPTIONAL {
    SELECT ?s1
    { ?s1 ?p2 ?o2 }
  }
}

produces the correct plan:

(project (?test ?s1)
  (leftjoin
    (disjunction
      (assign ((?test <http://localhost/t1>))
        (bgp (triple <http://localhost/t1> ?p1 ?o1)))
      (assign ((?test <http://localhost/t2>))
        (bgp (triple <http://localhost/t2> ?p1 ?o1))))
    (project (?s1)
      (bgp (triple ?s1 ?/p2 ?/o2)))))



> Filter optimization messes up when a nested select is present in the same block
> -------------------------------------------------------------------------------
>
>                 Key: JENA-432
>                 URL: https://issues.apache.org/jira/browse/JENA-432
>             Project: Apache Jena
>          Issue Type: Bug
>          Components: ARQ, Optimizer
>    Affects Versions: Jena 2.10.0
>            Reporter: Simon Helsen
>            Assignee: Andy Seaborne
>             Fix For: Jena 2.10.1
>
>
> The following test query:
> {noformat}
> SELECT ?test ?s1
> WHERE {
>   ?test ?p1 ?o1.
>   FILTER ( ?test = <http://localhost/t1> || ?test = <http://localhost/t2> )  
>   OPTIONAL {
>     SELECT ?s1
>     { ?s1 ?p2 ?o2 }
>   }
> }
> {noformat}
> produces the following plan:
> {noformat}
> (project (?test ?s1)
>   (disjunction
>     (table empty)
>     (table empty)))
> {noformat}
> Something goes wrong with the FILTER expansion. As a workaround, we observed that the following variation:
> {noformat}
> SELECT ?test ?s1
> WHERE {
>   { ?test ?p1 ?o1.
>     FILTER ( ?test = <http://localhost/t1> || ?test = <http://localhost/t2> )  
>   }
>   OPTIONAL {
>     SELECT ?s1
>     { ?s1 ?p2 ?o2 }
>   }
> }
> {noformat}
> produces the correct plan:
> {noformat}
> (project (?test ?s1)
>   (leftjoin
>     (disjunction
>       (assign ((?test <http://localhost/t1>))
>         (bgp (triple <http://localhost/t1> ?p1 ?o1)))
>       (assign ((?test <http://localhost/t2>))
>         (bgp (triple <http://localhost/t2> ?p1 ?o1))))
>     (project (?s1)
>       (bgp (triple ?s1 ?/p2 ?/o2)))))
> {noformat}



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