Re: How can i be certain autovacuum is causing reuse if table still grows

[MichaelDBA <MichaelDBA@xxxxxxxxxxx>]

Hi Keith,

I think statistics are also reset and not persistent through restarts when the pg_ctl option "-m immediate" is used when shutting down PG since it forces recovery mode when starting PG back up.  By the way, for PostgreSQL Aurora, statistics are reset automatically every time aurora forces PG to restart or reboot or the user selects that option manually.  I reported this as a bug with Aurora a few months ago.  They said it was not a bug, but a feature that the might implement in the future.  YUK.

Regards,
Michael Vitale


Keith Fiske wrote on 8/4/2020 6:25 PM:

On Tue, Aug 4, 2020 at 3:54 PM Scott Ribe <scott_ribe@xxxxxxxxxxxxxxxx> wrote:

> On Aug 4, 2020, at 12:31 PM, Sidney Aloisio Ferreira Pryor <sidney@xxxxxxxxxxx> wrote:
>
> Beside this, i saw on pg_stat_tables and the vacuum and autovacuum count for this table is 0.

Those values are not persistent; they are only since the last start of PG.

This is not correct. Statistics are persistent through restarts. They are only reset during specific cases such as a crash or a major version upgrade. They can also be reset at any time manually.

--

Keith Fiske
Senior Database Engineer
Crunchy Data - http://crunchydata.com