spark-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Yin Huai (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (SPARK-9740) first/last aggregate NULL behavior
Date Tue, 11 Aug 2015 20:43:46 GMT

    [ https://issues.apache.org/jira/browse/SPARK-9740?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14682460#comment-14682460
] 

Yin Huai commented on SPARK-9740:
---------------------------------

Thanks. I will change the behavior to respecting nulls.

> first/last aggregate NULL behavior
> ----------------------------------
>
>                 Key: SPARK-9740
>                 URL: https://issues.apache.org/jira/browse/SPARK-9740
>             Project: Spark
>          Issue Type: Sub-task
>          Components: SQL
>            Reporter: Herman van Hovell
>            Assignee: Yin Huai
>
> The FIRST/LAST aggregates implemented as part of the new UDAF interface, return the first
or last non-null value (if any) found. This is a departure from the behavior of the old FIRST/LAST
aggregates and from the FIRST_VALUE/LAST_VALUE aggregates in Hive. These would return a null
value, if that happened to be the first/last value seen. SPARK-9592 tries to 'fix' this behavior
for the old UDAF interface.
> Hive makes this behavior configurable, by adding a skipNulls flag. I would suggest to
do the same, and make the default behavior compatible with Hive.



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

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org


Mime
View raw message