Re: [SQL] PostgreSQL to Oracle - Mailing list pgsql-general

From David Fetter
Subject Re: [SQL] PostgreSQL to Oracle
Date
Msg-id 20070316174404.GC8169@fetter.org
Whole thread Raw
In response to Re: [SQL] PostgreSQL to Oracle  (Reece Hart <reece@harts.net>)
Responses Re: [SQL] PostgreSQL to Oracle  ("Jonah H. Harris" <jonah.harris@gmail.com>)
List pgsql-general
On Fri, Mar 16, 2007 at 10:18:56AM -0700, Reece Hart wrote:
> On Thu, 2007-03-15 at 16:20 -0400, Robert Treat wrote:
> > Do you find [HSODBC] works well?  I've used it from some older
> > Oracle instances connecting back into PostgreSQL and the results I
> > had have been flakey at best.
>
> - The real nail in the coffin seemed to be that there was no way to
> push predicates to the remote side. This mean that a remote relation
> was materialized locally in order to join with local data and that
> we'd never get reasonable performance for cross-database joins
> (which, perhaps, it's not designed to do).

DBI-Link has a way to push predicates to the remote side, but you have
to do it manually because DBI-Link is a user-space application, i.e.
it doesn't have access to PostgreSQL's planner.

Let me know if you have questions on how this works :)

Cheers,
D
--
David Fetter <david@fetter.org> http://fetter.org/
phone: +1 415 235 3778        AIM: dfetter666
                              Skype: davidfetter

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