Re: Should the docs have a warning about pg_stat_reset()?

On 2019-Apr-10, Bruce Momjian wrote:

> On Thu, Apr 11, 2019 at 04:14:11AM +1200, David Rowley wrote:

> > I still think we should start with a warning about pg_stat_reset().
> > People are surprised by this, and these are just the ones who notice:
> > 
> > https://www.postgresql.org/message-id/CAB_myF4sZpxNXdb-x=weLpqBDou6uE8FHtM0FVerPM-1J7phkw@mail.gmail.com
> > 
> > I imagine there are many others just suffering from bloat due to
> > auto-vacuum not knowing how many dead tuples there are in the tables.
> 
> OK, let me step back.  Why are people resetting the statistics
> regularly?  Based on that purpose, does it make sense to clear the
> stats that effect autovacuum?

I agree that we should research that angle.  IMO resetting stats should
be seriously frowned upon.  And if they do need to reset some counters
for some valid reason, offer a mechanism that leaves the autovac-
guiding counters alone.

IMO the answer for $SUBJECT is yes.

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Álvaro Herrera                https://www.2ndQuadrant.com/
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