Re: Exposing the stats snapshot timestamp to SQL

Matt Kelly <mkellycs@gmail.com> writes:
>> Yeah.  The only use-case that's been suggested is detecting an
>> unresponsive stats collector, and the main timestamp should be plenty for
>> that.

> The problem with doing highly granular snapshots is that the postgres
> counters are monotonically increasing, but only when stats are published.
> Currently you have no option except to divide by the delta of now() between
> the polling intervals. If you poll every 2 seconds the max error is about
> .5/2 or 25%.  It makes reading those numbers a bit noisy.  Using
> (snapshot_timestamp_new
> - snapshot_timestamp_old) as the denominator in that calculation should
> help to smooth out that noise and show a clearer picture.

Ah, interesting!  Thanks for pointing out another use case.
        regards, tom lane