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Message-ID: <dcc563d10807231343x5d07acdfu85d3eba3ec6afc3@mail.gmail.com>
Date: Wed, 23 Jul 2008 14:43:25 -0600
From: "Scott Marlowe" <scott.marlowe@gmail.com>
To: Miernik <public@public.miernik.name>
Subject: Re: how to fix problem then when two queries run at the same time,
	it takes longer to complete then if run in sequence
Cc: pgsql-performance@postgresql.org
In-Reply-To: <20080723203203.31C4.0.NOFFLE@turbacz.local>
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References: <20080723152112.30A4.0.NOFFLE@turbacz.local>
	<dcc563d10807231025s617c6b16neb93c6348a658cdb@mail.gmail.com>
	<20080723203203.31C4.0.NOFFLE@turbacz.local>

On Wed, Jul 23, 2008 at 2:32 PM, Miernik <public@public.miernik.name> wrote:
> Scott Marlowe <scott.marlowe@gmail.com> wrote:
>> won't ever run into.  Why such an incredibly limited virtual machine?
>> Even my cell phone came with 256 meg built in two years ago.
>
> Because I don't want to spend too much money on the machine rent, and a
> 48 MB RAM Xen is about all I can get with a budget of 100$ per year.
> Well, there are a few providers which will give me a 128 MB Xen for that
> money, but will the difference in performance be worth the hassle to
> switch providers? My current provider gives me almost perfect
> relaliability for that 100$ and I don't know how the providers which
> give more RAM for the same money perform, maybe they are often down or
> something. And spending more then 100$ yearly on this would be really
> overkill. My thing runs fine, only a bit slow, but reasonable. I just
> want to find out if I could maybe make it better with a little tweaking.
> Can I expect it to work at least three times faster on 128 MB RAM?
> Getting 256 MB would certainly cost too much. Or maybe there are some
> providers which can give me much more performance PostgreSQL server with
> at least several GB of storage for well... not more then 50$ per year.
> (because I must still rent another server to run and SMTP server and few
> other small stuff).
>
> My DB has several tables with like 100000 to 1 million rows each,
> running sorts, joins, updates etc on them several times per hour.
> About 10000 inserts and selects each hour, the whole DB takes 1.5 GB on
> disk now, 500 MB dumped.
>
> If I could shorten the time it takes to run each query by a factor of 3
> that's something worth going for.

Well, my guess is that by running under Xen you're already sacrificing
quite a bit of performance, and running it with only 48 Megs of ram is
making it even worse.  But if your budget is $100 a year, I guess
you're probably stuck with such a setup.  I would see if you can get a
trial Xen at the other hosts with 128M or more of memory and compare.