Hi,
Ken's approach of having a joint data type and unioning the streams is
good. This will work seamlessly with checkpoints. Timo (in CC) used the
same approach to implement a prototype of a multi-way join.
A Tuple won't work though because the Tuple serializer does not support
null fields. You c
Thanks for the Tuple suggestion, I may use that. I was asking about building a
custom operator (just an idea). I have since decided I can decompose the
problem into pairs of streams and emit a stream to the next CoFlatMap to get
the result I need. Now to see if the idea works ...
Michael
>
Hi Michael,
There isn’t an operator that takes three (or more) streams, AFAIK.
There is a CoFlatMapFunction that takes two different streams in, which could
be used for some types of joins.
Streaming joins are (typically) windowed (bounded), by time/count/something, so
if you can maintain the
In my case I have more elaborate logic to select data from the streams. They
are not all the same logical type, though I may be able to represent them as
the same Java type. My main question is whether it is technically feasible to
have a single operator that takes multiple streams as input.
