From: | Alvaro Herrera <alvherre(at)commandprompt(dot)com> |
---|---|
To: | Arjen van der Meijden <acm(at)tweakers(dot)net> |
Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: Reducing stats collection overhead |
Date: | 2007-07-31 03:07:07 |
Message-ID: | 20070731030707.GA7628@alvh.no-ip.org |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Arjen van der Meijden wrote:
> Afaik Tom hadn't finished his patch when I was testing things, so I don't
> know. But we're in the process of benchmarking a new system (dual quad-core
> Xeon) and we'll have a look at how it performs in the postgres 8.2dev we
> used before, the stable 8.2.4 and a fresh HEAD-checkout (which we'll call
> 8.3dev). I'll let you guys (or at least Tom) know how they compare in our
> benchmark.
So, ahem, did it work? :-)
> On 18-5-2007 15:12 Alvaro Herrera wrote:
>> Tom Lane wrote:
>>> Arjen van der Meijden told me that according to the tweakers.net
>>> benchmark, HEAD is noticeably slower than 8.2.4, and I soon confirmed
>>> here that for small SELECT queries issued as separate transactions,
>>> there's a significant difference. I think much of the difference stems
>>> from the fact that we now have stats_row_level ON by default, and so
>>> every transaction sends a stats message that wasn't there by default
>>> in 8.2. When you're doing a few thousand transactions per second
>>> (not hard for small read-only queries) that adds up.
>> So, did this patch make the performance problem go away?
--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2007-07-31 03:36:34 | Re: Machine available for community use |
Previous Message | Alvaro Herrera | 2007-07-31 03:00:30 | Re: Quick idea for reducing VACUUM contention |