(2011/10/08 1:06), Kohei KaiGai wrote:
> What is the reason why the foreign join is not pushed down?
> Maybe, injected Sort plan prevent the planner to consider both side of
> relations being foreign scan owned by same server? I'm still
> investigating the reason.
Thanks for your testing.
I'm not sure, but I think that Sort plan node would not be the reason
because it's an element of merge join. Maybe some wrong points would be
in my join method consideration.
In my assumption, ft1 and ft2 should be joined first (because such join
has very low costs) and then that result and lt3 should be joined with
one of local join methods, such as merge join and hash join.
I'll try your example soon.
Regards,
--
Shigeru Hanada