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https://issues.apache.org/jira/browse/HIVE-4160?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13627722#comment-13627722
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Steve Loughran commented on HIVE-4160:
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We couldn't have a copy of the doc in PDF stuck up at the same time as the
editable one could we?
> Vectorized Query Execution in Hive
> ----------------------------------
>
> Key: HIVE-4160
> URL: https://issues.apache.org/jira/browse/HIVE-4160
> Project: Hive
> Issue Type: New Feature
> Reporter: Jitendra Nath Pandey
> Assignee: Jitendra Nath Pandey
> Attachments: Hive-Vectorized-Query-Execution-Design.docx,
> Hive-Vectorized-Query-Execution-Design-rev2.docx
>
>
> Hive query execution engine currently processes one row at a time. A single
> row of data goes through all the operators before next row can be processed.
> This mode of processing is very inefficient in terms of CPU usage. Research
> has demonstrated that this yields very low instructions per cycle [MonetDB].
> Also currently hive heavily relies on lazy deserialization and data columns
> go through a layer of object inspectors that identify column type,
> de-serialize data and determine appropriate expression routines in the inner
> loop. These layers of virtual method calls further slow down the processing.
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