Re: parallel foreign scan

I think you are trying collecting data from multple kafka
server. This means each server has a dedicate foreign table on a
dedicate foreign server. Parallel execution doesn't fit in that
case since it works on single base relation (or a
table). Parallel append/merge append look a bit different but
actually is the same in the sense that one base relation is
scanned on multiple workers. Even if you are trying to fetch from
one kafka stream on multiple workers, I think the fdw driver
doesn't support parallel scanning anyway.