Re: Which parameters are only used on startup?

On Mon, Dec 22, 2025 at 07:29:10PM -0500, Tom Lane wrote:
> Bruce Momjian <bruce@momjian.us> writes:
> > On Wed, Nov 26, 2025 at 09:34:18AM +0000, PG Doc comments form wrote:
> >> Clarify that ssl_cert_file and ssl_key_file are only read on startup --
> >> implying that the params can be changed and the files moved to the new
> >> location/name without requiring a restart. Of course a restart is good to
> >> validate that the params and files are configured correctly.
> 
> > The docs say that you can only change this in postgresql.conf or on the
> > command line.  Changes to postgresql.conf requires pg_ctl reload or
> > something similar.
> 
> The actual problem with this change request is that it's wrong.
> We've supported changing ssl_cert_file --- either the GUC value
> or the file contents --- via "pg_ctl reload" or equivalent for
> years now (cf. commits de41869b6, 6667d9a6d).  So I don't see
> anything wrong with the docs text as it stands.

I had trouble parsing his text too but I think the original poster's
point was that changing these values don't affect a connected session.
When the original poster says restart, I think he/she means restart the
session, not the postmaster, but I am not 100% clear on that either.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  Do not let urgent matters crowd out time for investment in the future.