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    • Type: Sub-task
    • Status: Open
    • Priority: Medium
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: None
    • Component/s: None
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      Description

      The EXPLAIN reports some kinds of errors as reported by the operators in the plan during evaluation.

      1. typeError : The number of SPARQL type errors.

      Type errors caused by FILTER expressions caused through unbound variables (which may be a data issue) are not included at the time being (at least we believe this is true, it needs to be verified as part of this bug). We could extend things to note such errors when they appear in a FILTER because a required variable is not bound. This would give us a means to characterize the issue of potential FILTER problems as it appears in the data as well.

      Example:

      SELECT * WHERE {
       ?s :p1 ?o1
       OPTIONAL { ?s :p2 ?o2 }
       FILTER(?o1=?o2)
      }
      

      with data

      :s1 :p1 :o1
      

      would raise such a runtime type error, because ?o2 will be unbound when evaluating the FILTER. It would be nice to have such things reported (although they do not necessarily imply problems with the query).

      Systap/metaphacts should modify the code to track the additional counter. Maginfo can then integrate it into the EXPLAIN page.

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            Assignee:
            bryanthompson bryanthompson
            Reporter:
            michaelschmidt michaelschmidt
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              Created:
              Updated: