Perhaps a clarification to what Damian said: It is shown in the (HTML) table at the link you shared [1] what happens when you get null values for a key.
We also have slightly better join documentation at [2], the content/text of which we are currently migrating over to the official Apache Kafka documentation for the Streams API (under kafka.apache.org/documentation/streams). [1] https://cwiki.apache.org/confluence/display/KAFKA/Kafka+Streams+Join+Semantics#KafkaStreamsJoinSemantics-KTable-KTableJoin [2] https://docs.confluent.io/current/streams/developer-guide.html#kstream-kstream-join On Fri, Sep 8, 2017 at 3:19 PM, Damian Guy <damian....@gmail.com> wrote: > It is shown in the table what happens when you get null values for a key. > > On Fri, 8 Sep 2017 at 12:31 Kamal Chandraprakash < > kamal.chandraprak...@gmail.com> wrote: > > > Hi Kafka Users, > > > > KTable-KTable Join Semantics is explained in detailed [here][1]. But, > > it's not clear when the input record is <K:NULL>, some times the output > > records are generated and in some cases it's not. > > > > It will be helpful, if someone explain on how the output records are > > generated for all the 3 types of joins on receiving a record with NULL > > value. > > > > [1]: https://cwiki.apache.org/confluence/display/KAFKA/ > > Kafka+Streams+Join+Semantics#KafkaStreamsJoinSemantics-KTable-KTableJoin > > > > -- Kamal > > >
