Re: pgsql_fdw, FDW for PostgreSQL server

(2012/02/14 15:15), Shigeru Hanada wrote:
> (2012/02/13 20:50), Etsuro Fujita wrote:
>> The patches have been applied, but role-related regression tests failed
>> in my environment. I fixed it in a similar fashion of
>> /src/test/regress/sql/foreign_data.sql. Please find attached a updated
>> patch for the regression tests.
>
> Good catch, thanks. I'll revise pgsql_fdw tests little more.
>
>> BTW, What do you think about this?
>>
>> http://archives.postgresql.org/pgsql-hackers/2012-01/msg00229.php
>
> I'm sorry that I've left the thread unfinished... I've given up to
> propose Join-push-down of foreign tables for 9.2, because it will take a
> while to achieve general semantics mapping for join push-down and WHERE
> clause push-down. For 9.2, I'm proposing pgsql_fdw which has WHERE
> clause push-down for built-in elements which are free from collation.
> I'd like to go back to that item after 9.2 development enters beta or
> RC, hopefully :)

OK. But my question was about the PlanForeignScan API. As discussed at
that thread, it would have to change the PlanForeignScan API to let the
FDW generate multiple paths and dump them all to add_path instead of
returning a FdwPlan struct. With this change, I think it would also
have to add a new FDW API that is called from create_foreignscan_plan()
and lets the FDW generate foreignscan plan for the base relation scanned
by the best path choosed by postgres optimizer for itself. What do you
think about it?

Best regards,
Etsuro Fujita