Re: should we enable log_checkpoints out of the box?

On Sun, Oct 31, 2021 at 10:24:38PM +0100, Michael Banck wrote:
> On Sun, Oct 31, 2021 at 01:16:33PM -0700, Andres Freund wrote:
> > Shrug. It's based on many years of doing or being around people doing
> > postgres support escalation shifts. And it's not like log_checkpoints
> > incurs meaningful overhead or causes that much log volume.
> 
> It could be a bit of reverse-survivorship-bias, i.e., you're only seeing
> the pathological cases, while 99% of the Postgres installations out
> there just hum along fine without anybody ever having to look at the
> checkpoint entries in the log.
> 
> But yeah, for serious production instances, it makes sense to turn that
> option on, but I'm not convinced it should be the default.

Yes, I agree with this analysis. There is a sense that people who
regularly diagnose Postgres problems want this information in the logs
by default, while the majority of sites might want silent logs for
normal query activity.

I realize in this thread that Robert Haas mentioned foreign key
violations that would like also appear in logs, but those are
ERROR/WARNING etc. messages that can be filtered out with
log_min_message.  I think if we want to offer a more verbose set of
analytic output, by default or not, we might want to relabel them as
something other than LOG messages so they can be filtered out with
log_min_messages.

-- 
  Bruce Momjian          https://momjian.us
  EDB                                      https://enterprisedb.com

  If only the physical world exists, free will is an illusion.