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From "Namit Jain (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HIVE-625) Use of BinarySortableSerDe for serialization of the value between map and reduce boundary
Date Fri, 10 Jul 2009 15:33:16 GMT

    [ https://issues.apache.org/jira/browse/HIVE-625?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12729677#action_12729677
] 

Namit Jain commented on HIVE-625:
---------------------------------

But, is it a good idea to always do so ?

Can't you come up with another testcase where the opposite will hold.
The reducer has a highly selective filter at the beginning, followed by a select.
In binarysortableserde, all the columns are read, whereas in lazysimleserde, most of the columns
are not even materialized.


> Use of BinarySortableSerDe for serialization of the value between map and reduce boundary
> -----------------------------------------------------------------------------------------
>
>                 Key: HIVE-625
>                 URL: https://issues.apache.org/jira/browse/HIVE-625
>             Project: Hadoop Hive
>          Issue Type: Improvement
>          Components: Query Processor
>            Reporter: Zheng Shao
>            Assignee: Zheng Shao
>         Attachments: HIVE-625.1.patch
>
>
> We currently use LazySimpleSerDe which serializes double to text format. Before we have
LazyBinarySerDe, we should switch to BinarySortableSerDe because that's still much faster
than LazySimpleSerDe.

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