From: Simon Riggs <simon@2ndquadrant.com>
To: Jignesh K. Shah <J.K.Shah@Sun.COM>
Cc: Josh Berkus <josh@agliodbs.com>
Cc: pgsql-hackers@postgresql.org
Subject: Re: Overhauling GUCS
Date: Mon, 02 Jun 2008 17:29:17 +0100
Message-ID: <1212424157.4120.371.camel@ebony.site> (raw)
In-Reply-To: <484418D9.5040608@sun.com>
References: <48409D1E.3070208@agliodbs.com>
<1212219274.4120.191.camel@ebony.site>
<484418D9.5040608@sun.com>
On Mon, 2008-06-02 at 11:59 -0400, Jignesh K. Shah wrote:
>
> Simon Riggs wrote:
> >
> > Some other problems I see with GUCs
> >
> > * It's not possible to set one parameter depending upon the setting of
> > another.
> >
>
> To me this is more critical.. Most people I have seen will increase one
> or few but not all parameters related to memory which can result in loss
> of performance and productivity in figuring out.
>
> What happened to AvailRAM setting and base all memory gucs on that.
> Ideally PostgreSQL should only create one big memory pool and allow all
> other variables to change runtime via dba or some tuner process or
> customized application as long as total is less than the allocated
> shared_memory and local_memory settings. (This will also reduce the need
> of restarting Postgres if a value needs to be changed)
Agreed.
Right now, we can't even do that in code, let alone in config file.
If we had a smart_memory_config = on then we'd be able to say in the
backend:
if (smart_memory_config)
{
other_thing = 0.1 * Nbuffers;
}
but the GUCs are evaluated in alphabetical order, without any way of
putting dependencies between them. So they are notionally orthogonal.
--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Training, Services and Support
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To: pgsql-hackers@postgresql.org
Cc: simon@2ndquadrant.com, J.K.Shah@Sun.COM, josh@agliodbs.com
Subject: Re: Overhauling GUCS
In-Reply-To: <1212424157.4120.371.camel@ebony.site>
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