Re: Database and Table stats gets reset automatically

On Mon, 25 Jul 2016, 10:10 p.m. Adrian Klaver, <adrian(dot)klaver(at)aklaver(dot)com>
wrote:

> On 07/24/2016 09:58 PM, Sameer Kumar wrote:
> > Hi,
> >
> > I have PostgreSQL v9.4.4 running in my environment. It has been up for
> > over 2 years now. I noticed that suddenly the statistics have been reset
> > and all the stat tables/columns got restarted from.
>
> Any of these happen?:
>
> https://www.postgresql.org/docs/9.4/static/monitoring-stats.html
> ". When recovery is performed at server start (e.g. after immediate
> shutdown, server crash, and point-in-time recovery), all statistics
> counters are reset."
>

Nope. This has happened on the standby database. The counter on the master
database are still running fine.

There was a period of few days about a month ago when I had to reverse the
roles but then I switched them back to the way they were. But recently, I
have not done anything which brings the server out of recovery.

> >
> > This happened 2 weeks ago. I noticed only recently after I looked at the
> > plot over last week (which dipped suddenly for "number of tuples
> > returned", "number of conflicts" etc).
>
> Any change in procedures the last two weeks?
>

Nope. The scripts to capture this data to csv file is very much the same.

> >
> > The columns which got reset are from pg_stat_database,
> > pg_stat_user_tables, pg_stat_bgwriter
> >
> > As far I know no one has fired pg_stat_reset or pg_stat_reset_shared.
> >
> > I noticed that the last largest value is from pg_stat_user_tables.
> > tup_returned (470440261405). Does the statistics get reset automatically
>
> tup_returned is in pg_stat_database.
>

Sorry my bad (a copy paste mistake). Yes I was referring to tup_returned
from pg_stat_database. But the various stats in pg_stat_user_tables have
also been reset.

> What does the stats_reset field show in pg_stat_database?
>

It says a timestamp from 18th July 2016. Infact all the other statistics
views have the same timestamp.

> > when the value for one of the statistics reaches the high number
> > supported by int4?
> >
> > I am running on Red Hat 6.7.
> >
> > Regards
> > Sameer
> > --
> > --
> > Best Regards
> > Sameer Kumar | DB Solution Architect
> > *ASHNIK PTE. LTD.*
> >
> > 101 Cecil Street, #11-11 Tong Eng Building, Singapore 069 533
> >
> > T: +65 6438 3504 | M: +65 8110 0350 | www.ashnik.com
> >
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com
>
--
--
Best Regards
Sameer Kumar | DB Solution Architect
*ASHNIK PTE. LTD.*

101 Cecil Street, #11-11 Tong Eng Building, Singapore 069 533

T: +65 6438 3504 | M: +65 8110 0350 | www.ashnik.com