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https://issues.apache.org/jira/browse/HIVE-4689?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13690881#comment-13690881
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Ashutosh Chauhan commented on HIVE-4689:
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I am not super aware of this config. What exactly does it govern? It seems like
it for buffering rows pulled from reducer iterator in memory. So, we are
trading speed with memory utilization with config. Is that correct?
In that case think it makes sense to disable this altogether for outer join
case.
> For outerjoins, joinEmitInterval might make wrong result
> --------------------------------------------------------
>
> Key: HIVE-4689
> URL: https://issues.apache.org/jira/browse/HIVE-4689
> Project: Hive
> Issue Type: Bug
> Components: Query Processor
> Reporter: Navis
> Assignee: Navis
> Attachments: HIVE-4689.D11211.1.patch
>
>
> Alias filter tag is calculated for each group and used for outer joins. But
> if joinEmitInterval is smaller than the group size, pre-matured alias filter
> tag would be used and might introduce different(wrong) result.
> It can be observed in join_1to1.q test but I cannot imagine proper solution
> which does not override intention of joinEmitInterval. Should it be disabled
> for outer joins?
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