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https://issues.apache.org/jira/browse/HIVE-18359?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16336285#comment-16336285
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Prasanth Jayachandran commented on HIVE-18359:
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Rebased the patch.
To handle mapperIsAbsent, we probably can rely on some path in filesystem that
will be atomically cleaned up by GBY mapper. Alternate approach is for
optimizer to detect such cases, and introduce an empty split (or something
similar to NullScanOptimizer) to make sure atleast one mapper is launched.
[~kgyrtkirk] any chance you had created a jira for it? If not I can create a
separate ticket.
> Extend grouping set limits from int to long
> -------------------------------------------
>
> Key: HIVE-18359
> URL: https://issues.apache.org/jira/browse/HIVE-18359
> Project: Hive
> Issue Type: Bug
> Affects Versions: 3.0.0
> Reporter: Prasanth Jayachandran
> Assignee: Prasanth Jayachandran
> Priority: Major
> Attachments: HIVE-18359.1.patch, HIVE-18359.2.patch,
> HIVE-18359.3.patch, HIVE-18359.4.patch, HIVE-18359.5.patch, HIVE-18359.6.patch
>
>
> Grouping sets is broken for >32 columns because of usage of Int for bitmap
> (also GROUPING__ID virtual column). This assumption breaks grouping
> sets/rollups/cube when number of participating aggregation columns is >32.
> The easier fix would be extend it to Long for now. The correct fix would be
> to use BitSets everywhere but that would require GROUPING__ID column type to
> binary which will make predicates on GROUPING__ID difficult to deal with.
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