Re: PostgreSQL Configuration Tool for Dummies

[Greg Smith <gsmith(at)gregsmith(dot)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(at)gregsmith(dot)com http://www.gregsmith.com Baltimore, MD