Re: FDW for PostgreSQL

Stephen Frost <sfrost@snowman.net> writes:
> * Tom Lane (tgl@sss.pgh.pa.us) wrote:
>> ... The only way to
>> make this sane at all would be to provide user control of which
>> operations go to which connections; which is inherent in dblink's API
>> but is simply not a concept in the FDW universe.  And I don't want to
>> try to plaster it on, either.

> This concern would make a lot more sense to me if we were sharing a
> given FDW connection between multiple client backends/sessions; I admit
> that I've not looked through the code but the documentation seems to
> imply that we create one-or-more FDW connection per backend session and
> there's no sharing going on.

Well, ATM postgres_fdw shares connections across tables and queries;
but my point is that that's all supposed to be transparent and invisible
to the user.  I don't want to have API features that make connections
explicit, because I don't think that can be shoehorned into the FDW
model without considerable strain and weird corner cases.
        regards, tom lane