hive-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Namit Jain (JIRA)" <>
Subject [jira] [Commented] (HIVE-3403) user should not specify mapjoin to perform sort-merge bucketed join
Date Thu, 18 Oct 2012 19:16:04 GMT


Namit Jain commented on HIVE-3403:

Had an offline review with Kevin - the following came out of that:

1. The policy to choose the big table should take the average size of the partition into account.
   We dont need to change the existing policy, can add a new policy.
2. The new policy should give preference to a table with no partitions/ 1 partition.
3. If one of the tables is small enough to fit in memory, there is no need to perform sort-merge
join. The
   policy should check that. Eventually, that check should be removed, and that should be
handled by the physical
   optimizer - will file a new jira for that.

> user should not specify mapjoin to perform sort-merge bucketed join
> -------------------------------------------------------------------
>                 Key: HIVE-3403
>                 URL:
>             Project: Hive
>          Issue Type: Bug
>            Reporter: Namit Jain
>            Assignee: Namit Jain
>         Attachments: hive.3403.1.patch
> Currently, in order to perform a sort merge bucketed join, the user needs
> to set hive.optimize.bucketmapjoin.sortedmerge to true, and also specify the 
> mapjoin hint.
> The user should not specify any hints.

This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see:

View raw message