From: Craig James <craig_james@emolecules.com>
To: Scott Carey <scott@richrelevance.com>
Cc: Carlos Moreno <morenopg@mochima.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: "Mysterious" issues with newly installed 8.3
Date: Thu, 09 Oct 2008 19:45:25 -0700
Message-ID: <48EEC1C5.4090204@emolecules.com> (raw)
In-Reply-To: <a1ec7d000810091734k60cee7d7qb95470936ad461c1@mail.gmail.com>
References: <48EE98FE.60100@mochima.com>
<a1ec7d000810091734k60cee7d7qb95470936ad461c1@mail.gmail.com>
Scott Carey wrote:
> On Thu, Oct 9, 2008 at 4:51 PM, Carlos Moreno <morenopg@mochima.com
> <mailto:morenopg@mochima.com>> wrote:
>
>
> Ok, I know that such an open and vague question like this one
> is... well, open and vague... But still.
>
> The short story:
>
> Just finished an 8.3.4 installation on a new machine, to replace
> an existing one; the new machine is superior (i.e., higher
> performance) in virtually every way --- twice as much memory,
> faster processor, faster drives, etc.
>
> I made an exact copy of the existing database on the new
> machine, and the exact same queries run on both reveal that
> the old machine beats the new one by a factor of close to 2 !!!!
> (i.e., the same queries run close to twice as fast on the old
> machine!!!)
>
> To make things worse: the old machine is in operation, under
> normal workload (and right now the system may be around
> peak time), and the new machine is there sitting doing nothing;
> just one user logged in using psql to run the queries --- *no-one
> and nothing* is connecting to the new server.
>
> So... What's going on???
Did you do an ANALYZE on the new database after you cloned it? I was suprised by this too, that after doing a pg_dump/pg_restore, the performance sucked. But it was simply because the new database had no statistics yet.
Craig
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To: pgsql-performance@postgresql.org
Cc: craig_james@emolecules.com, scott@richrelevance.com, morenopg@mochima.com
Subject: Re: "Mysterious" issues with newly installed 8.3
In-Reply-To: <48EEC1C5.4090204@emolecules.com>
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