Re: Reducing power consumption on idle servers

On Mon, Nov 28, 2022 at 5:27 AM Thomas Munro <thomas(dot)munro(at)gmail(dot)com> wrote:
>
> "The trigger_file and promote_trigger_file have been removed." was
> missing some words. I've also added a sentence to say which releases
> were involved, to make it like nearby paragraphs about other obsolete
> stuff.

LGTM.

> The funny thing about that "obsolete" appendix is that it's intended
> as a URL-preserving way to document the recovery.conf file's demise in
> r12. It doesn't look like the right place to document ongoing changes
> to recovery-related GUCs in general. In this particular case it's
> sort of OK because the old trigger_file GUC was indeed in
> recovery.conf, so it's not completely irrelevant. So maybe it's OK?
> Perhaps in future, in a separate commit, we could have a new appendix
> "Obsolete settings" that has an alphabetical list of the fallen?

Tracking down history to figure out and add all the removed/renamed
settings under a new appendix seems a tedious task. The best is to
look into corresponding release notes to figure out which ones have
been removed/renamed/altered IMO.

FWIW, it's been a while (3 major releases have happened) since
recovery.conf was removed, I think we need to do away with
appendix-obsolete-recovery-config.sgml someday.

> The main documentation of pg_promote() etc now has "The parameter
> <varname>promote_trigger_file</varname> has been removed" in the
> places where the GUC was previously mentioned. Perhaps we should just
> remove the mentions completely (it's somehow either too much and not
> enough information), but I'm OK with leaving those in for now until
> some better place exists for historical notes.

+1 for the way it is in the v12 patch i.e. specifying removal of it in
the docs. However, I don't see any reason to keep the traces of it in
the code, can we remove "Use of trigger file via promote_trigger_file
is now fully removed." sentence in the code below?

+ * Wait for more WAL to arrive, when we will be woken
+ * immediately by the WAL receiver. Use of trigger file
+ * via promote_trigger_file is now fully removed.
*/

> So this is the version I will push unless someone sees anything more
> to tweak about the documentation.

Thanks.

--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com