[jira] [Commented] (JENA-587) SELECT DISTINCT returns duplicate results

["Rob Vesse (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/JENA-587?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13819993#comment-13819993 ] 

Rob Vesse commented on JENA-587:
--------------------------------

More recent of versions automatically optimise DISTINCT -> REDUCED which may leave some duplicates.

Due to the predictable way in which TDB returns scan results and ARQ executes joins for most queries this is a non-issue since the two queries will be equivalent since REDUCED in ARQ eliminates neighbouring non-distinct solutions.

This behaviour can be turned off like so:

{noformat}
ARQ.getContext().set(ARQ.optDistinctToReduced, false)
{noformat}

> SELECT DISTINCT returns duplicate results
> -----------------------------------------
>
>                 Key: JENA-587
>                 URL: https://issues.apache.org/jira/browse/JENA-587
>             Project: Apache Jena
>          Issue Type: Bug
>          Components: ARQ
>    Affects Versions: Jena 2.11.0
>            Reporter: Veyriere
>         Attachments: bug Jena2.11.0.zip
>
>
> SELECT DISTINCT returns duplicate results. Attaching a small quads dump and the query to reproduce with TDB
> Reproduced with Jena 2.11.0 and Jena 2.10.1 (was working with 2.7.4)



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