Re: Spinlock performance improvement proposal

> Tom Lane wrote:
> >
> <snip>
> > I think the default NBuffers (64) is too low to give meaningful
> > performance numbers, too. I've been thinking that maybe we should
> > raise it to 1000 or so by default. This would trigger startup failures
> > on platforms with small SHMMAX, but we could tell people to use -B until
> > they get around to fixing their kernel settings. It's been a long time
> > since we fit into a 1-MB shared memory segment at the default settings
> > anyway, so maybe it's time to select somewhat-realistic defaults.
> > What we have now is neither very useful nor the lowest common
> > denominator...
>
> How about a startup error message which gets displayed when used with
> untuned settings (i.e. the default settings), maybe unless an option
> like -q (quiet) is given?
>
> My thought is the server should operate, but let the new/novice admin
> know they need to configure PostgreSQL properly. Would probably be a
> good reminder for experienced admins if they forget too.
>
> Maybe something simple like pg_ctl shell script message, or something
> proper like a postmaster start-up check.

Yes, this seems like the way to go, probably something in the postmaster
log file. For single-user developers, we want it to start but we want
production machines to tune it. In fact, picking a higher number for
these values may be almost as far off as our defaults.

--
Bruce Momjian | http://candle.pha.pa.us
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