Message-ID: <4602C921.3070303@modgraph-usa.com>
Date: Thu, 22 Mar 2007 10:21:21 -0800
From: "Craig A. James" <cjames@modgraph-usa.com>
User-Agent: Thunderbird 1.5.0.10 (Windows/20070221)
MIME-Version: 1.0
To: Steve Atkins <steve@blighty.com>,  pgsql-performance@postgresql.org
Subject: Re: Performance of count(*)
References: <Pine.LNX.4.62.0703221149210.13747@wr-linux02>
	<200703221208.19358.albert@sedifa.com>
	<Pine.LNX.4.64.0703221323590.1503@ismoli.solenovo.jns>
	<20070322141807.GE11402@mathom.us>
	<46029DE3.9030505@modgraph-usa.com>
	<4602A15B.7000908@wildenhain.de>
	<4602BB19.9050306@modgraph-usa.com>
	<228F06CD-3642-4A42-813A-648285A3BDBC@blighty.com>
In-Reply-To: <228F06CD-3642-4A42-813A-648285A3BDBC@blighty.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

Steve Atkins wrote:
> As long as you're ordering by some row in the table then you can do that in
> straight SQL.
> 
> select a, b, ts from foo where (stuff) and foo > X order by foo limit 10
> 
> Then, record the last value of foo you read, and plug it in as X the next
> time around.

We've been over this before in this forum: It doesn't work as advertised.  Look for postings by me regarding the fact that there is no way to tell the optimizer the cost of executing a function.  There's one, for example, on Oct 18, 2006.

> I think the problem is more that most web developers aren't very good
> at using the database, and tend to fall back on simplistic, wrong, 
> approaches
> to displaying the data. There's a lot of monkey-see, monkey-do in web
> UI design too, which doesn't help.

Thanks, I'm sure your thoughtful comments will help me solve my problem.  Somehow. ;-)

Craig