Re: ALTER SYSTEM between upgrades

On Tue, Jul 14, 2020 at 12:52:23PM +0200, Daniel Gustafsson wrote:
> > On 14 Jul 2020, at 01:58, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
>
> > I am creating a new thread to discuss the question raised by Alvaro of
> > how many ALTER SYSTEM settings are lost during major upgrades. Do we
> > properly document that users should migrate their postgresql.conf _and_
> > postgresql.auto.conf files during major upgrades? I personally never
> > thought of this until now.
>
> Transferring postgresql.conf is discussed to some degree in the documentation
> for pg_upgrade:
>
> 11. Restore pg_hba.conf
> If you modified pg_hba.conf, restore its original settings. It might
> also be necessary to adjust other configuration files in the new
> cluster to match the old cluster, e.g. postgresql.conf.
>
> .. as well as upgrading via pg_dumpall:
>
> 4. Restore your previous pg_hba.conf and any postgresql.conf
> modifications.
>
> One can argue whether those bulletpoints are sufficient for stressing the
> importance, but it's at least mentioned. There is however no mention of
> postgresql.auto.conf which clearly isn't helping anyone, so we should fix that.
>
> Taking that a step further, maybe we should mention additional config files
> which could be included via include directives? There are tools out there who
> avoid changing the users postgresql.conf by injecting an include directive
> instead; they might've placed the included file alongside postgresql.conf.

I have developed the attached pg_upgrade doc patch to address this.

--
Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EnterpriseDB https://enterprisedb.com

The usefulness of a cup is in its emptiness, Bruce Lee