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Posted to users@kafka.apache.org by Kamal Chandraprakash <ka...@gmail.com> on 2017/09/08 11:31:19 UTC
KTable-KTable Join Semantics on NULL Key
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
Re: KTable-KTable Join Semantics on NULL Key
Posted by Michael Noll <mi...@confluent.io>.
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 <da...@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.chandraprakash@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
> >
>
Re: KTable-KTable Join Semantics on NULL Key
Posted by Damian Guy <da...@gmail.com>.
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.chandraprakash@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
>