[jira] [Commented] (HIVE-12369) Native Vector GroupBy

["Matt McCline (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HIVE-12369?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16102777#comment-16102777 ] 

Matt McCline commented on HIVE-12369:
-------------------------------------

#5 cratered.

> Native Vector GroupBy
> ---------------------
>
>                 Key: HIVE-12369
>                 URL: https://issues.apache.org/jira/browse/HIVE-12369
>             Project: Hive
>          Issue Type: Bug
>          Components: Hive
>            Reporter: Matt McCline
>            Assignee: Matt McCline
>            Priority: Critical
>         Attachments: HIVE-12369.01.patch, HIVE-12369.02.patch, HIVE-12369.05.patch, HIVE-12369.06.patch
>
>
> Implement Native Vector GroupBy using fast hash table technology developed for Native Vector MapJoin, etc.
> Patch is currently limited to a single Long key, aggregation on Long columns, no more than 31 columns.
> 3 new classes introduces that stored the count in the slot table and don't allocate hash elements:
> {noformat}
>   COUNT(column)  VectorGroupByHashOneLongKeyCountColumnOperator      
>   COUNT(key)     VectorGroupByHashOneLongKeyCountKeyOperator            
>   COUNT(*)       VectorGroupByHashOneLongKeyCountStarOperator           
> {noformat}
> And a new class that aggregates a single Long key:
> {noformat}
>   VectorGroupByHashOneLongKeyOperator
> {noformat}



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