[
https://issues.apache.org/jira/browse/KAFKA-14049?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17563510#comment-17563510
]
Matthias J. Sax commented on KAFKA-14049:
-----------------------------------------
{quote}Null Values in the Stream for a Left Join would indicate a Tombstone
Message
{quote}
This does not make sense to me. A KStream is an event/fact stream and thus
there are not delete/tombstone semantics. Only _changelogs_ have tombstone
semantics, but changelogs are modeled as `KTables` in Kafka Streams.
I still tend to agree that the current semantics are not ideal, but it's hard
to fix without introducing ambiguity (and the reason to drop them, is to avoid
ambiguity).
I guess a current workaround would be, to implement the join using a
`transform()` (or similar) – should not be too complicated.
> Relax Non Null Requirement for KStreamGlobalKTable Left Join
> ------------------------------------------------------------
>
> Key: KAFKA-14049
> URL: https://issues.apache.org/jira/browse/KAFKA-14049
> Project: Kafka
> Issue Type: Improvement
> Components: streams
> Reporter: Saumya Gupta
> Priority: Major
> Labels: beginner, newbie
>
> Null Values in the Stream for a Left Join would indicate a Tombstone Message
> that needs to propagated if not actually joined with the GlobalKTable
> message, hence these messages should not be ignored .
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
