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From "Joydeep Sen Sarma (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HIVE-1116) alter table rename should rename hdfs location of table as well
Date Thu, 28 Jan 2010 20:25:36 GMT

    [ https://issues.apache.org/jira/browse/HIVE-1116?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12806074#action_12806074
] 

Joydeep Sen Sarma commented on HIVE-1116:
-----------------------------------------

yeah - positive.  it might work 'once'. but if u repeat the recipe - it will fail because
'a' points to 'a_tmp' next time.

> alter table rename should rename hdfs location of table as well
> ---------------------------------------------------------------
>
>                 Key: HIVE-1116
>                 URL: https://issues.apache.org/jira/browse/HIVE-1116
>             Project: Hadoop Hive
>          Issue Type: Bug
>            Reporter: Joydeep Sen Sarma
>
> if the location is not an external location - this would be safer.
> the problem right now is that it's tricky to use the drop and rename way of writing new
data into a table. consider:
> Initialization block:
> drop table a_tmp
> create table a_tmp like a;
> Loading block:
> load data <newdata> into a_tmp;
> drop table a;
> alter table a_tmp rename to a;
> this looks safe. but it's not. if one runs this multiple times - then data is lost (since
'a' is pointing to 'a_tmp''s location after any iteration. and dropping table 'a' blows away
loaded data in the next iteration). 
> if the location is being managed by Hive - then 'rename' should switch location as well.

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