Re: upgraded to pgsql 8.2.4, getting worse performance then 7.4.x

Find the attached Postgres.conf file. I am using 8.1 Version in Lab.

I haven't done any changes to this conf file to improve the performance.

What are the attributes needs to be modified in the conf file to improve the
performance?

I am looking forward for your assistance.

Regards,
Hanu

On 6/2/07, Douglas J Hunley <doug(at)hunley(dot)homeip(dot)net> wrote:
>
> Hello great gurus of performance:
> Our 'esteemed' Engr group recently informed a customer that in their
> testing,
> upgrading to 8.2.x improved the performance of our J2EE
> application "approximately 20%", so of course, the customer then tasked me
> with upgrading them. We dumped their db, removed pgsql, installed the
> 8.2.4
> rpms from postgresql.org, did an initdb, and the pg_restored their data.
> It's
> been about a week now, and the customer is complaining that in their
> testing,
> they are seeing a 30% /decrease/ in general performance. Of course, our
> Engr
> group is being less than responsive, and I have a feeling all they're
> doing
> is googling for answers, so I'm turning to this group for actual
> assistance :)
> I'd like to start by examining the poistgresql.conf file. Under 7.4.x, we
> had
> spent the better part of their 2 years as a customer tuning and tweaking
> setting. I've attached the file that was in place at the time of upgrade.
> I
> did some cursory googling of my own, and quickly realized that enough has
> changed in v8 that I'm not comfortable making the exact same modification
> to
> their new config file as some options are new, some have gone away, etc.
> I've
> attached the existing v8 conf file as well.
> I'd really like it if someone could assist me in determining which of the
> v8
> options need adjusted to be 'functionally equivalent' to the v7 file.
> Right
> now, my goal is to get the customer back to the previous level of
> performance, and only then pursue further optimization. I can provide any
> and
> all information needed, but didn't know what to include initially, so I've
> opted to include the minimal :)
> The DB server in question does nothing else, is running CentOS 4.5, kernel
> 2.6.9-55.ELsmp. Hyperthreading is disabled in the BIOS and there are 2
> Xeon
> 3.4Ghz cpus. There is 8Gb of RAM in the machine, and another 8Gb of swap.
>
> Thank you in advance for any and all assistance you can provide.
> --
> Douglas J Hunley (doug at hunley.homeip.net) - Linux User #174778
> http://doug.hunley.homeip.net
>
> Handy Guide to Modern Science:
> 1. If it's green or it wiggles, it's biology.
> 2. If it stinks, it's chemistry.
> 3. If it doesn't work, it's physics.
>
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--
With best regards,
Hanumanthappa Kurubar
Mobile: 98 801 800 65