Re: Really really slow select count(*)

+1

this is exactly what I was looking for at the time: a -t (configtest)
option to pg_ctl

and I think it should fall back to lower shared buffers and log it.

SHOW ALL; would show the used value

On Mon, Feb 7, 2011 at 11:30 AM, Marti Raudsepp <marti(at)juffo(dot)org> wrote:

> On Mon, Feb 7, 2011 at 05:03, Craig Ringer <craig(at)postnewspapers(dot)com(dot)au>
> wrote:
> > What would possibly help would be if Pg could fall back to lower
> > shared_buffers automatically, screaming about it in the logs but still
> > launching. OTOH, many people don't check the logs, so they'd think their
> > new setting had taken effect and it hadn't - you've traded one usability
> > problem for another. Even if Pg issued WARNING messages to each client
> > that connected, lots of (non-psql) clients don't display them, so many
> > users would never know.
> >
> > Do you have a suggestion about how to do this better? The current
> > approach is known to be rather unlovely, but nobody's come up with a
> > better one that works reasonably and doesn't trample on other System V
> > shared memory users that may exist on the system.
>
> We could do something similar to what Apache does -- provide distros
> with a binary to check the configuration file in advance. This check
> program is launched before the "restart" command, and if it fails, the
> server is not restarted.
>
> Regards,
> Marti
>