[pgpool-general: 1533] Re: foreign data wrappers support?

[Lonni J Friedman]

On Wed, Mar 27, 2013 at 4:10 PM, Tatsuo Ishii <ishii at postgresql.org> wrote:
>> Greetings,
>> I checked the official dox, but didn't see any mention of how foreign
>> data wrappers (FDW:
>> http://www.postgresql.org/docs/9.2/static/sql-createserver.html ) are
>> handled inside pgpool.  Is it completely transparent, such that the
>> same rules for write queries apply to queries that involve foreign
>> data wrappers?
>
> Yes, I think so. I have tried file_fdw with pgpool-II streaming
> replication setting and it seems working.
>
>> I'm mostly thinking & planning for 9.3 when a postgres FDW will be
>> supported ( http://www.postgresql.org/docs/devel/static/postgres-fdw.html
>> ).  This opens up a lot of new & interesting possibilities, especially
>> with respect to clustering & load balancing, as it will be (somewhat)
>> trivially possible to access different clusters from each other.
>
> Can you elaborate on clustering & load balancing by using pgsql_fdw
> with pgpool-II?
> --

What I was envisioning (granted this is all theoretical, I haven't
tried to do any of it yet) was using pgsql_fdw to link two completely
separate postgres clusters, both of which would have their own pgpool
instances.  The 'CREATE SERVER' command would reference the port
number of the second pgpool instance, rather than the postgres server
itself.  As a result, any of the tables associated with the foreign
postgres server would actually have their SQL queries going directly
over the second pgpool instance.  I'm wondering if this should work as
far as pgpool is concerned?

thanks