[jira] [Assigned] (SPARK-16721) Lead/lag needs to respect nulls

["Yin Huai (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/SPARK-16721?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Yin Huai reassigned SPARK-16721:
--------------------------------

    Assignee: Yin Huai

> Lead/lag needs to respect nulls 
> --------------------------------
>
>                 Key: SPARK-16721
>                 URL: https://issues.apache.org/jira/browse/SPARK-16721
>             Project: Spark
>          Issue Type: Bug
>          Components: SQL
>    Affects Versions: 2.0.0
>            Reporter: Yin Huai
>            Assignee: Yin Huai
>
> Seems 2.0.0 changes the behavior of lead and lag to ignore nulls. This PR is changing the behavior back to 1.6's behavior, which is respecting nulls.
> For example 
> {code}
> SELECT
> b,
> lag(a, 1, 321) OVER (ORDER BY b) as lag,
> lead(a, 1, 321) OVER (ORDER BY b) as lead
> FROM (SELECT cast(null as int) as a, 1 as b
> UNION ALL
> select cast(null as int) as id, 2 as b) tmp
> {code}
> This query should return 
> {code}
> +---+----+----+
> |  b| lag|lead|
> +---+----+----+
> |  1| 321|null|
> |  2|null| 321|
> +---+----+----+
> {code}
> instead of 
> {code}
> +---+---+----+
> |  b|lag|lead|
> +---+---+----+
> |  1|321| 321|
> |  2|321| 321|
> +---+---+----+
> {code}



--
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