Re: Auto-tuning work_mem and maintenance_work_mem

On Thu, Oct 10, 2013 at 07:24:26AM -0700, Kevin Grittner wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>
> > I actually had the thought that it might be something we'd integrate
> > *into* initdb.  So you'd do initdb --system-memory 8GB or something
> > like that and it would do the rest.  That'd be slick, at least IMHO.
>
> How would you handle the case that the machine (whether physical or
> a VM) later gets more RAM?  That's certainly not unheard of with
> physical servers, and with VMs I'm not sure that the database
> server would necessarily go through a stop/start cycle for it.

Yes, going from a non-dedicated to a dedicated database server, adding
RAM, or moving the cluster to another server could all require an initdb
to change auto-tuned values. This is why I think we will need to
auto-tune in the backend, rather than via initdb. I do think an
available_mem parameter for initdb would help though, to be set in
postgresql.conf.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ Everyone has their own god. +