Some databases (MySQL I think) ship several example configurations sized for
different installations. The default is very safe, but it's simply a matter
of choosing between "small.conf", "medium.conf", "big.conf", "huge.conf" and
copying it over the standard "tiny.conf" file.
Each config file contains comments near the top of the file that specify
suggested hardware requirements for using it.
Providing a similar series of config files for postgres would probably cut
the traffic to the performance mailing list significantly and end the need
for discussions such as this. (not that I mind the discussion)
--
Matthew Nuzum
www.bearfruit.org
cobalt@bearfruit.org
> -----Original Message-----
> From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
> Sent: Wednesday, June 11, 2003 3:28 PM
> To: Kaarel
> Cc: Justin Clift; Jay O'Connor; pgsql-general@postgresql.org
> Subject: Re: Postgres performance comments from a MySQL user
>
> Kaarel <kaarel@future.ee> writes:
> > This makes me wonder why is the default configuration so conservative?
>
> There are still a lot of platforms where desirable settings will cause
> the database to fail to start, because the default kernel limits on
> shared memory are still set for 1980s-vintage hardware.
>
> We have had a policy for a long time that we'd rather the out-of-the-box
> settings be guaranteed to start than that they be optimal for
> performance. No one is going to get as far as testing performance
> if the system won't start for them.
>
> Having said that, though, I do wonder whether we couldn't bump them up a
> little. Are there still any live platforms where the default SHMMAX is
> less than 4 MB? (There was discussion of this a month or two back on
> pghackers, but no conclusion.)
>
> regards, tom lane