Re: Fix for erroneous warning on Shutdown

Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> Tom Lane wrote:
>> I could argue that a client-driven process that issues CHECKPOINT every
>> few seconds is equally deserving of a warning. The only thing wrong is
>> that the HINT is inapplicable ... but that's why it's a HINT and not
>> part of the main message.

> Also consider they could have issued a checkpoint right after the system
> did one. Yuck.

> When I added the warning I hoped to only have it happen for full logs
> and not CHECKPOINT, but I guess I couldn't and someone else realized
> that and added that clearer comment, or originally I could do that, but
> since it has been moved into the bgwriter, it can't anymore.

I believe the original implementation in the postmaster had a somewhat
different set of bugs ;-). IIRC it did not react to manual checkpoints
but it did confuse WAL checkpoints with timeout-driven checkpoints.
The present bgwriter can distinguish the third but not the first two.

If we were willing to take the time to generalize the
backend-to-bgwriter signaling mechanism then we could distinguish
WAL-driven checkpoints from manually issued checkpoints. I'm sort of
intending to do that anyway. The question stands though: why isn't it
appropriate to warn of overly-frequently-issued manual checkpoints?

regards, tom lane