From: Greg Smith <gsmith@gregsmith.com>
To: pgsql-performance@postgresql.org
Subject: Re: PostgreSQL Configuration Tool for Dummies
Date: Wed, 20 Jun 2007 02:24:03 -0400 (EDT)
Message-ID: <Pine.GSO.4.64.0706200155290.16657@westnet.com> (raw)
In-Reply-To: <200706191254.09777.josh@agliodbs.com>
References: <A3AC4FA47DC0B1458C3E5396E685E63302395E63@SAB-DC1.sab.uiuc.edu>
<Pine.LNX.4.64.0706191205320.25045@asgard.lang.hm>
<200706191254.09777.josh@agliodbs.com>
On Tue, 19 Jun 2007, Josh Berkus wrote:
> I don't think the "mostly reads / mostly writes" question covers anything,
> nor is it likely to produce accurate answers. Instead, we need to ask the
> users to characterize what type of application they are running:
> T1) Please characterize the general type of workload you will be running on
> this database. Choose one of the following four...
We've hashed through this area before, but for Lance's benefit I'll
reiterate my dissenting position on this subject. If you're building a
"tool for dummies", my opinion is that you shouldn't ask any of this
information. I think there's an enormous benefit to providing something
that takes basic sizing information and gives conservative guidelines
based on that--as you say, "safe, middle-of-the-road values"--that are
still way, way more useful than the default values. The risk in trying to
make a complicated tool that satisfies all the users Josh is aiming his
more sophisticated effort at is that you'll lose the newbies.
Scan the archives of this mailing list for a bit. If you look at what
people discover they've being nailed by, it's rarely because they need to
optimize something like random_page_cost. It's usually because they have
a brutally wrong value for one of the memory or vacuum parameters that are
very easy to provide reasonable suggestions for without needing a lot of
information about the server.
I wouldn't even bother asking how many CPUs somebody has for what Lance is
building. The kind of optimizations you'd do based on that are just too
complicated to expect a tool to get them right and still be accessible to
a novice.
--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD
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To: pgsql-performance@postgresql.org
Cc: gsmith@gregsmith.com
Subject: Re: PostgreSQL Configuration Tool for Dummies
In-Reply-To: <Pine.GSO.4.64.0706200155290.16657@westnet.com>
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