[jira] Updated: (HIVE-74) Hive can use CombineFileInputFormat for when the input are many small files

["dhruba borthakur (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-74?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

dhruba borthakur updated HIVE-74:
---------------------------------

    Attachment: hiveCombineSplit.patch

Allow Hive to use CombineInputFormat. This will not compile against 0.17 and 0.19 because CombineInputFormat is available only in 0.20 (HADOOP-4565).

> Hive can use CombineFileInputFormat for when the input are many small files
> ---------------------------------------------------------------------------
>
>                 Key: HIVE-74
>                 URL: https://issues.apache.org/jira/browse/HIVE-74
>             Project: Hadoop Hive
>          Issue Type: Improvement
>          Components: Query Processor
>            Reporter: dhruba borthakur
>            Assignee: dhruba borthakur
>             Fix For: 0.2.0
>
>         Attachments: hiveCombineSplit.patch, hiveCombineSplit.patch
>
>
> There are cases when the input to a Hive job are thousands of small files. In this case, there is a mapper for each file. Most of the overhead for spawning all these mappers can be avoided if Hive used CombineFileInputFormat introduced via HADOOP-4565

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