You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@hive.apache.org by "Amareshwari Sriramadasu (JIRA)" <ji...@apache.org> on 2010/08/16 13:45:17 UTC

[jira] Updated: (HIVE-741) NULL is not handled correctly in join

     [ https://issues.apache.org/jira/browse/HIVE-741?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Amareshwari Sriramadasu updated HIVE-741:
-----------------------------------------

    Attachment: patch-741.txt

Attaching a simple patch which fixes JoinOperator (for reduce-side joins) and MapJoinOperator (for map-side joins) to not group the null join keys together. 
Any comments on the approach/code are welcome.
Verified that SMBMapJoinOperator already filters nulls properly.

> NULL is not handled correctly in join
> -------------------------------------
>
>                 Key: HIVE-741
>                 URL: https://issues.apache.org/jira/browse/HIVE-741
>             Project: Hadoop Hive
>          Issue Type: Bug
>            Reporter: Ning Zhang
>            Assignee: Amareshwari Sriramadasu
>         Attachments: patch-741.txt
>
>
> With the following data in table input4_cb:
> Key        Value
> ------       --------
> NULL     325
> 18          NULL
> The following query:
> {code}
> select * from input4_cb a join input4_cb b on a.key = b.value;
> {code}
> returns the following result:
> NULL    325    18   NULL
> The correct result should be empty set.
> When 'null' is replaced by '' it works.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.