I have been trying to get my head wrapped around some of the internals of beam so I can come up with an architecture/plan for STORM-1757 <https://issues.apache.org/jira/browse/STORM-1757> / BEAM-9 <https://issues.apache.org/jira/browse/BEAM-9>.
I see that there are Sources and Sinks. Sources can be unbounded, but there appears to be no equivalent to an unbounded Sink. What I do find are things like WriteToBigQuery which despite some internal complexity ends up being an idempotent transform producing a PDone. Is this the intended way for data to be output from a streaming DAG? I will likely have more questions as I dig more into state checkpointing, etc. Thanks, Bobby Evans
