"David G. Johnston" <david.g.johnston@gmail.com> writes:
>> Alas, those config values are remembered in postmaster.opts. But I don't
>> want that.
> I don’t know where this file is even documented ATM but my understanding is
> it just shows you the values used during the last startup.
It does more, per the pg_ctl man page:
postmaster.opts
If this file exists in the data directory, pg_ctl (in restart
mode) will pass the contents of the file as options to postgres,
unless overridden by the -o option. The contents of this file are
also displayed in status mode.
It seems totally reasonable for "pg_ctl restart" to re-apply those
switches. If you don't want that, don't use "restart", but stop
and start.
Or you could just remove the file.
regards, tom lane