Greg's book is highly recommended, and in my opinion a "must" for anyone doing serious work with Postgres.
> -----Original Message-----
> From: pgsql-performance-owner@postgresql.org [mailto:pgsql-performance-
> owner@postgresql.org] On Behalf Of Anibal David Acosta
> Sent: Friday, June 10, 2011 7:19 AM
> To: 'Craig Ringer'
> Cc: tv@fuzzy.cz; pgsql-performance@postgresql.org
> Subject: Re: [PERFORM] how much postgres can scale up?
>
> Excellent.
>
> Thanks I'll buy and read that book :)
>
>
> Thanks!
>
>
>
> -----Mensaje original-----
> De: Craig Ringer [mailto:craig@postnewspapers.com.au]
> Enviado el: viernes, 10 de junio de 2011 09:13 a.m.
> Para: Anibal David Acosta
> CC: tv@fuzzy.cz; pgsql-performance@postgresql.org
> Asunto: Re: [PERFORM] how much postgres can scale up?
>
> On 06/10/2011 08:56 PM, Anibal David Acosta wrote:
> > The version is Postgres 9.0
> > Yes, I setup the postgres.conf according to instructions in the
> > http://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server
> >
> >
> > Cool, I will check this
> > http://wiki.postgresql.org/wiki/Logging_Difficult_Queries
> >
> > Looks like great starting point to find bottleneck
> >
> > But so, Is possible in excellent conditions that two connections
> duplicate the quantity of transactions per second?
>
> For two connections, if you have most of the data cached in RAM or you
> have lots of fast disks, then sure. For that matter, if they're
> synchronized scans of the same table then the second transaction might
> perform even faster than the first one!
>
> There are increasing overheads with transaction synchronization, etc
> with number of connections, and they'll usually land up contending for
> system resources like RAM (for disk cache, work_mem, etc), disk I/O,
> and CPU time. So you won't generally get linear scaling with number of
> connections.
>
> Greg Smith has done some excellent and detailed work on this. I highly
> recommend reading his writing, and you should consider buying his
> recent book "PostgreSQL 9.0 High Performance".
>
> See also:
>
> http://wiki.postgresql.org/wiki/Performance_Optimization
>
> There have been lots of postgresql scaling benchmarks done over time,
> too. You'll find a lot of information if you look around the wiki and
> Google.
>
> --
> Craig Ringer
>
>
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