Re: Reseting statistics counters - Mailing list pgsql-performance

From Tomas Vondra
Subject Re: Reseting statistics counters
Date
Msg-id 52A25E5C.9090405@fuzzy.cz
Whole thread Raw
In response to Re: Reseting statistics counters  (Strahinja Kustudić <strahinjak@nordeus.com>)
List pgsql-performance
On 16.11.2013 20:49, Strahinja Kustudić wrote:
> Sorry for the late reply, but as far as I know when you run
> pg_stat_reset() you should always run analyze manually of the
> database to populate the statistics.

Why?

There are two kinds of stats in the database - stats used by the planner
(common column values, histograms, ...) and runtime stats. pg_stat_reset
only deals with the latter, it won't discard histograms or anything like
that.

And runnning analyze won't magically populate the runtime stats - for
example how could it populate number of sequential/index scans or the
timestamp of the last autovacuum?

The only thing that may be influenced by this is autovacuum, because
this will remove timestamp of the last run on the tables, number of
deleted/dead tuples etc. So it will be invoked on all tables, collecting
this info.

regards
Tomas


pgsql-performance by date:

Previous
From: Richard Huxton
Date:
Subject: Re: postgres performance
Next
From: Tomas Vondra
Date:
Subject: Re: WAL + SSD = slow inserts?