Hi everyone, Gentle ping on this thread. Looking forward to feedback on the KIP!
Best, Lucy Liu On Fri, May 15, 2026 at 4:19 PM Lucy Liu <[email protected]> wrote: > Hello everyone, > > I would like to start a discussion on KIP-1340 Pass Join Key to > `ValueJoinerWithKey` in Streams-GlobalKTable Joins > < > https://cwiki.apache.org/confluence/display/KAFKA/KIP-1340%3A+Pass+Join+Key+to+%60ValueJoinerWithKey%60+in+Streams-GlobalKTable+Joins > > > > This proposal aims to introduce joinOnMappedKey and leftJoinOnMappedKey, > new KStream methods that pass the mapped join key (the result of the > user-supplied KeyValueMapper) into ValueJoinerWithKey for > stream-globalTable joins. The existing join/leftJoin overloads pass the > stream record's key into the joiner instead, contradicting KIP-149's > contract that readOnlyKey is the join key and silently producing wrong > values if a joiner intends to read the real join key. The existing > overloads will be deprecated and removed in a future major release. > > Best regards, > Lucy Liu >
