[jira] [Commented] (TAJO-1265) min(), max() does not handle null properly

["ASF GitHub Bot (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/TAJO-1265?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14255449#comment-14255449 ] 

ASF GitHub Bot commented on TAJO-1265:
--------------------------------------

GitHub user sirpkt opened a pull request:

    https://github.com/apache/tajo/pull/315

    TAJO-1265: min(), max() does not handle null properly

    min() and max() handle null value separately from non-null values.
    It computes min() or max() among non-null values first.
    If no non-null value exists, they return null value.
    Implementation style of min() and max() is also changed that 
    there are abstract classes of Min and Max common for all the data types
    and only type specific methods are implemented for each type. 

You can merge this pull request into a Git repository by running:

    $ git pull https://github.com/sirpkt/tajo TAJO-1265

Alternatively you can review and apply these changes as the patch at:

    https://github.com/apache/tajo/pull/315.patch

To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

    This closes #315
    
----
commit 46c5dd47deac696b19536ee5bb78667006bad8a5
Author: sirpkt <si...@apache.org>
Date:   2014-12-22T05:26:04Z

    TAJO-1265: min(), max() does not handle null properly

----


> min(), max() does not handle null properly
> ------------------------------------------
>
>                 Key: TAJO-1265
>                 URL: https://issues.apache.org/jira/browse/TAJO-1265
>             Project: Tajo
>          Issue Type: Bug
>            Reporter: Keuntae Park
>            Assignee: Keuntae Park
>            Priority: Minor
>
> In other DBs like oracle and postgreSQL, 
> null is excluded from calculation of min() and max() value until there is no non-null value in the given column, in which case, it returns null. 
> However, current implementation of Tajo considers null as
> 0 for int or long column, 0.0 for float or double column, or "" for text column.
> It needs to handle null value separately from non-null values in min() and max() calculation. 



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)