I'm just thinking we can try to encourage users to migrate from XX to XXWithKey in the docs, giving this as one good example that the latter can help you distinguish different scenarios whereas the former cannot.
On Fri, Aug 4, 2023 at 6:32 PM Matthias J. Sax <mj...@apache.org> wrote: > > Guozhang, > > thanks for pointing out ValueJoinerWithKey. In the end, it's just a > documentation change, ie, point out that the passed in key could be > `null` and similar? > > -Matthias > > > On 8/2/23 3:20 PM, Guozhang Wang wrote: > > Thanks Florin for the writeup, > > > > One quick thing I'd like to bring up is that in KIP-149 > > (https://cwiki.apache.org/confluence/display/KAFKA/KIP-149%3A+Enabling+key+access+in+ValueTransformer%2C+ValueMapper%2C+and+ValueJoiner) > > we introduced ValueJoinerWithKey which is aimed to enhance > > ValueJoiner. It would have a benefit for this KIP such that > > implementers can distinguish "null-key" v.s. "not-null-key but > > null-value" scenarios. > > > > Hence I'd suggest we also include the semantic changes with > > ValueJoinerWithKey, which can help distinguish these two scenarios, > > and also document that if users apply ValueJoiner only, they may not > > have this benefit, and hence we suggest users to use the former. > > > > > > Guozhang > > > > On Mon, Jul 31, 2023 at 12:11 PM Florin Akermann > > <florin.akerm...@gmail.com> wrote: > >> > >> https://cwiki.apache.org/confluence/display/KAFKA/KIP-962%3A+Relax+non-null+key+requirement+in+Kafka+Streams
