From: Tom Lane <tgl@sss.pgh.pa.us>
To: Heikki Linnakangas <heikki@enterprisedb.com>
Cc: Bruce Momjian <bruce@momjian.us>
Cc: Jim C. Nasby <jim@nasby.net>
Cc: pgsql-performance@postgresql.org
Subject: Re: Hints proposal
Date: Thu, 12 Oct 2006 12:24:16 -0400
Message-ID: <11204.1160670256@sss.pgh.pa.us> (raw)
In-Reply-To: <452E6565.4010400@enterprisedb.com>
References: <200610121519.k9CFJA416544@momjian.us>
<452E6565.4010400@enterprisedb.com>
Heikki Linnakangas <heikki@enterprisedb.com> writes:
> BTW: Do we make use of CHECK constraints in the planner?
Only for "constraint exclusion", and at the moment that's off by default.
The gating problem here is that if the planner relies on a CHECK
constraint, and then you drop the constraint, the previously generated
plan might start to silently deliver wrong answers. So I'd like to see
a plan invalidation mechanism in place before we go very far down the
path of relying on constraints for planning. That's something I'm going
to try to make happen for 8.3, though.
regards, tom lane
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, heikki@enterprisedb.com, bruce@momjian.us, jim@nasby.net
Subject: Re: Hints proposal
In-Reply-To: <11204.1160670256@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox