Re: Status of FDW pushdowns

Dimitri Fontaine <dimitri@2ndquadrant.fr> writes:
> Atri Sharma <atri.jiit@gmail.com> writes:
>> Can we add a function to the FDW API to define a SQL to foreign server
>> side conversion?

> I think that's not tenable. Even if you limit the discussion to the
> postgres_fdw, some queries against past version will stop working
> against new version (keywords changes, catalogs, default settings, etc).

> I don't think you want to embed a full parser of every supported FOREIGN
> version of PostgreSQL inside the postgres_fdw code, so I think the text
> of the view needs to be an opaque string.

I'm not real sure what this'd buy us that wouldn't be done as well or
better by creating a view on the remote side.  (IOW, there's nothing
that says that the remote object backing a foreign table can't be a
view.)
        regards, tom lane