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From "Josh Wills (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CRUNCH-545) Writing to HFiles starts a job per column family
Date Sun, 19 Jul 2015 16:15:05 GMT

    [ https://issues.apache.org/jira/browse/CRUNCH-545?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14632859#comment-14632859
] 

Josh Wills commented on CRUNCH-545:
-----------------------------------

+1

> Writing to HFiles starts a job per column family
> ------------------------------------------------
>
>                 Key: CRUNCH-545
>                 URL: https://issues.apache.org/jira/browse/CRUNCH-545
>             Project: Crunch
>          Issue Type: Improvement
>            Reporter: Gabriel Reid
>            Assignee: Gabriel Reid
>         Attachments: CRUNCH-545.patch, post.dot.png, pre.dot.png
>
>
> When writing to HFiles via {{HFileUtils.writeToHFilesForIncrementalLoad}}, a separate
MR job is started up per column family defined for the table, regardless of whether or not
there is any data for each of these column families.
> Each of the column family jobs runs over the full set of Cells, filters for the desired
column family, and then partitions the data.
> For tables with multiple column families, it would be a lot more efficient to sort/partition
all of the data together, and then split it out per column family afterwards.



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