Content-Type: text/plain;
  charset="iso-8859-1"
From: Josh Berkus <josh@agliodbs.com>
Reply-To: josh@agliodbs.com
Organization: Aglio Database Solutions
To: "JOE" <joe@piscitella.com>, <pgsql-sql@postgresql.org>
Subject: Re: union optimization in views
Date: Thu, 29 Aug 2002 10:52:39 -0700
References: <003d01c24f17$2d21ff00$c801a8c0@joe>
In-Reply-To: <003d01c24f17$2d21ff00$c801a8c0@joe>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Message-Id: <200208291052.39160.josh@agliodbs.com>

Joe,

> We are attempting to move a couple of systems from Oracle to Postgres but=
=20
can not do so without application rewrites due to the current use of views=
=20
with UNIONs and the criticality of the performances of these views.
>=20
> I was wondering if a decision has been made on the optimization with the=
=20
UNION clause in views.  There are many documents in the SQL archive showing=
=20
that the "push down" is not occuring and thus the use of UNION's in views i=
s=20
limited to case where the data set is small or performance is not a=20
consideration.  I also looked through the TODO list and didn't see anything=
=20
(of course I could have missed references).=20=20

I'd take this up on PGSQL-HACKERS.   The UNION VIEW optimization, last I=20
checked, was stalled mainly because nobody wanted to work on it.  Maybe you=
=20
can?

--=20
-Josh Berkus
 Aglio Database Solutions
 San Francisco