Re: how to fix problem then when two queries run at the same time, it takes longer to complete then if run in sequence - Mailing list pgsql-performance

From Scott Marlowe
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
Date
Msg-id dcc563d10807231025s617c6b16neb93c6348a658cdb@mail.gmail.com
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In response to how to fix problem then when two queries run at the same time, it takes longer to complete then if run in sequence  (Miernik <public@public.miernik.name>)
List pgsql-performance
On Wed, Jul 23, 2008 at 9:21 AM, Miernik <public@public.miernik.name> wrote:
> I have a PostgreSQL database on a very low-resource Xen virtual machine,
> 48 MB RAM. When two queries run at the same time, it takes longer to
> complete then if run in sequence. Is there perhaps a way to install
> something like a query sequencer, which would process queries in a FIFO
> manner, one at a time, even if a new query comes before the last one
> running is finished, it would not give the new query to the server
> before the one running now finishes? That would greatly improve
> performance.
>
> Any tips in general for running PostgreSQL on such low-resource machine?
>
> I have:
>
> shared_buffers = 5MB
> work_mem = 1024kB
>
> are these good values, or could perhaps changing something improve it a
> bit? Any other parameters to look at?

Well, you're basically working on a really limited machine there.  I'd
set shared buffers up by 1 meg at a time and see if that helps.  But
you're basically looking at a very narrow problem that most people
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.

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