Re: Really really slow select count(*)

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