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From "Eric Hanson (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (HIVE-4160) Vectorized Query Execution in Hive
Date Sat, 06 Apr 2013 01:02:09 GMT

     [ https://issues.apache.org/jira/browse/HIVE-4160?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Eric Hanson updated HIVE-4160:
------------------------------

    Attachment: Hive-Vectorized-Query-Execution-Design-rev2.docx

Added section on requirements for implementation of vectorized iterator, with respect to how
to load VectorizedRowBatch object on each call to next().
                
> 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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