[jira] [Commented] (SQOOP-1055) Add option to export from Hive use HQL query

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

    [ https://issues.apache.org/jira/browse/SQOOP-1055?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13696187#comment-13696187 ] 

Konstantinos commented on SQOOP-1055:
-------------------------------------

I urgently need this improvement. So I am willing to work on this. If anyone can help me with the part of source code I need to patch he will save me some time! Thanks! 
                
> Add option to export from Hive use HQL query
> --------------------------------------------
>
>                 Key: SQOOP-1055
>                 URL: https://issues.apache.org/jira/browse/SQOOP-1055
>             Project: Sqoop
>          Issue Type: Improvement
>            Reporter: Hari Sekhon
>
> Sqoop currently has a --query option for import but not for export.
> It would be nice if the export --query option supporting HiveQL could be added as users currently have to create a temporary table and then export that as a two step process with a full disk re-write of all the to-be-exported data to a new table before the sqoop export command is started.
> Since Sqoop executes a distributed map-only job, I believe certain queries such as joins that have to be done via a reduce phase will yield little performance improvement due to the map->reduce intermediate writes needing to be written anyway. However we could save on the final reduce phase writes and also turn this in to a more convenient one step instead two step process.

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