Yeah, we could make it more permissive that way. This is a discussion for the future when we do fix that operation, but it seems safest to support that join only when both streams have the exact same window configuration (otherwise there's no guarantee that the streams have any keys in common).
In such a situation, we wouldn't have to worry about enforcing it here. But for now, I was thinking to be strict about the common grace periods as a basic precaution against mixing window types. (even though the grace period isn't part of the windowed key). [ Full content available at: https://github.com/apache/kafka/pull/5567 ] This message was relayed via gitbox.apache.org for [email protected]
