Re: [HACKERS] Changing the default configuration (was Re:

Peter Eisentraut <peter_e(at)gmx(dot)net> writes:
> Tom Lane writes:
>> We could retarget to try to stay under SHMMAX=4M, which I think is
>> the next boundary that's significant in terms of real-world platforms
>> (isn't that the default SHMMAX on some BSDen?). That would allow us
>> 350 or so shared_buffers, which is better, but still not really a
>> serious choice for production work.

> What is a serious choice for production work?

Well, as I commented later in that mail, I feel that 1000 buffers is
a reasonable choice --- but I have to admit that I have no hard data
to back up that feeling. Perhaps we should take this to the
pgsql-perform list and argue about reasonable choices.

A separate line of investigation is "what is the lowest common
denominator nowadays?" I think we've established that SHMMAX=1M
is obsolete, but what replaces it as the next LCD? 4M seems to be
correct for some BSD flavors, and I can confirm that that's the
current default for Mac OS X --- any other comments?

regards, tom lane