[jira] [Closed] (FLINK-7755) Null values are not correctly handled by batch inner and outer joins

["Fabian Hueske (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/FLINK-7755?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Fabian Hueske closed FLINK-7755.
--------------------------------
       Resolution: Fixed
    Fix Version/s:     (was: 1.3.3)

Fixed in 1.4.0 with 2a6381553e48e0145655c0aadd173813de610aa7

> Null values are not correctly handled by batch inner and outer joins
> --------------------------------------------------------------------
>
>                 Key: FLINK-7755
>                 URL: https://issues.apache.org/jira/browse/FLINK-7755
>             Project: Flink
>          Issue Type: Bug
>          Components: Table API & SQL
>    Affects Versions: 1.4.0, 1.3.2
>            Reporter: Fabian Hueske
>            Assignee: Fabian Hueske
>            Priority: Blocker
>             Fix For: 1.4.0
>
>
> Join predicates of batch joins are not correctly evaluated according to three-value logic.
> This affects inner as well as outer joins.
> The problem is that some equality predicates are only evaluated by the internal join algorithms of Flink which are based on {{TypeComparator}}. The field {{TypeComparator}} for {{Row}} are implemented such that {{null == null}} results in {{TRUE}} to ensure correct ordering and grouping. However, three-value logic requires that {{null == null}} results to {{UNKNOWN}} (or null). The code generator implements this logic correctly, but for equality predicates, no code is generated.
> For outer joins, the problem is a bit tricker because these do not support code-generated predicates yet (see FLINK-5520). FLINK-5498 proposes a solution for this issue.
> We also need to extend several of the existing tests and add null values to ensure that the join logic is correctly implemented. 



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)