2014/1/24 Emmanuel Medernach <medernac@clermont.in2p3.fr>:
> Hello,
>
> I'm currently testing postgres_fdw feature on PostgreSQL 9.3.2 and I have
> some questions:
>
> - What are the limits to the number of foreign tables ?
As far as I know, there is no limit (beyond the usual PostgreSQL limits).
> - What is the current status about foreign joins push-down ?
Unless I'm mistaken (and no doubt someone will correct me if I am),
joins cannot be pushed down yet, only WHERE clauses for individual foreign
table rows.
To quote this article about PostgreSQL 9.3: http://lwn.net/Articles/550418/
'More work needs to be done in this area to make this a full "big data"
solution, however; Hanada hopes to add "push down" of joins, sorts,
and aggregates in future versions of PostgreSQL."
See also this thread:
http://www.postgresql.org/message-id/20131121150515.GC23976@momjian.us
Regards
Ian Barwick
