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From "Owen O'Malley (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HIVE-5562) Provide stripe level column statistics in ORC
Date Mon, 04 Nov 2013 17:35:18 GMT

    [ https://issues.apache.org/jira/browse/HIVE-5562?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13813037#comment-13813037
] 

Owen O'Malley commented on HIVE-5562:
-------------------------------------

Sorry, I missed looking at the new files. Additional comments:

* In Metadata, don't bother with getStripeStatistics and rename getStripeStatisticsList to
getStripeStatistics.
* Use package private for the Metadata constructor
* Use package private for StripeStastics constructor


> Provide stripe level column statistics in ORC
> ---------------------------------------------
>
>                 Key: HIVE-5562
>                 URL: https://issues.apache.org/jira/browse/HIVE-5562
>             Project: Hive
>          Issue Type: New Feature
>          Components: File Formats
>    Affects Versions: 0.13.0
>            Reporter: Prasanth J
>            Assignee: Prasanth J
>              Labels: orcfile
>             Fix For: 0.13.0
>
>         Attachments: HIVE-5562.1.patch.txt
>
>
> ORC maintains two levels of column statistics. Index statistics (for every rowgroup)
and file level column statistics for the entire file. It is useful to have stripe level column
statistics which will be intermediate to index and file statistics. The reason to maintain
stripe level statistics is that, the current input split computation logic is based on stripe
boundaries. So if stripe level statistics are available and if a stripe doesn't satisfy a
predicate condition then that entire stripe (also split) can be eliminated from split computation.



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