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  1. Blazegraph (by SYSTAP)
  2. BLZG-1095

ORDER_BY ordering not preserved by projection operator

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      The order of ORDER_BY is not always preserved by the PROJECTION operator. From the developers email list:

      > I updated the query to use the simple variable in ORDER BY, and the results are the same.
      >
      > Here is the exact query (with or without DISTINCT) for the linked results:
      >
      > PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
      > PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
      > PREFIX owl: <http://www.w3.org/2002/07/owl#>
      >
      > SELECT DISTINCT ?term ?string_label
      > WHERE
      > {
      > ?term rdf:type owl:Class .
      > ?term rdfs:label ?term_label .
      > BIND (STR(?term_label) AS ?string_label)
      > }
      > ORDER BY ?string_label
      >
      >
      > Results (same number of rows either way):
      > SELECT DISTINCT:
      > explain: https://dl.dropboxusercontent.com/u/6704325/bigdata/2014-11-6/with_distinct_explain.html
      > result: https://dl.dropboxusercontent.com/u/6704325/bigdata/2014-11-6/with_distinct_result.csv
      >
      > SELECT:
      > explain: https://dl.dropboxusercontent.com/u/6704325/bigdata/2014-11-6/no_distinct_explain.html
      > result: https://dl.dropboxusercontent.com/u/6704325/bigdata/2014-11-6/no_distinct_result.csv
      >
      > Thanks,
      > Jim
      >
      

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            Assignee:
            bryanthompson bryanthompson
            Reporter:
            bryanthompson bryanthompson
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