Re: constraint exclusion analysis caching

From: Gregory Stark <stark(at)enterprisedb(dot)com>
To: "Andrew Dunstan" <andrew(at)dunslane(dot)net>
Cc: "PostgreSQL-development" <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: constraint exclusion analysis caching
Date: 2008-05-09 14:14:42
Message-ID: 87d4nvef8t.fsf@oxford.xeocode.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

"Andrew Dunstan" <andrew(at)dunslane(dot)net> writes:

> Actual execution of the query in question was talking one tenth of that
> time.
>...
> but in principle it seems silly to keep paying the same penalty over and
> over again.

I would think constraint_exclusion only really makes sense if you're spending
a lot more time executing than planning queries. Either that means you're
preparing queries once and then executing them many many times or you're
planning much slower queries where planning time is insignificant compared to
the time to execute them.

--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com
Get trained by Bruce Momjian - ask me about EnterpriseDB's PostgreSQL training!

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2008-05-09 14:23:12 Re: [0/4] Proposal of SE-PostgreSQL patches
Previous Message Tom Lane 2008-05-09 14:01:44 Re: constraint exclusion analysis caching