Re: First draft of the PG 15 release notes - Mailing list pgsql-hackers

On Wed, Jun 29, 2022 at 10:08:08PM -0700, Noah Misch wrote:
> On Tue, Jun 28, 2022 at 04:35:45PM -0400, Bruce Momjian wrote:
> > > If you dump/reload an unmodified v14 template1 (as pg_dumpall and pg_upgrade
> > > do), your v15 template1 will have a v14 ACL on its public schema.  At that
> > > point, the fate of "newly-created databases in existing clusters" depends on
> > > whether you clone template1 or template0.  Does any of that detail belong
> > > here, or does the existing text suffice?
> > 
> > I think it is very confusing to have template0 have one value and
> > template1 have a different one, but as I understand it template0 will
> > only be used for pg_dump comparison, and that will keep template1 with
> > the same permissions, so I guess it is okay.
> 
> It's an emergent property of two decisions.  In the interest of backward
> compatibility, I decided to have v15 pg_dump emit GRANT for the public schema
> even when the source is an unmodified v14- database.  When that combines with
> the ancient decision that a pg_dumpall or pg_upgrade covers template1 but not
> template0, one gets the above consequences.  I don't see a way to improve on
> this outcome.

Thanks for the summary.

> > > >       permissions on the <literal>public</literal> schema has not
> > > >       been changed.  Databases restored from previous Postgres releases
> > > >       will be restored with their current permissions.  Users wishing
> > > >       to have the old permissions on new objects will need to grant
> > > 
> > > The phrase "old permissions on new objects" doesn't sound right to me, but I'm
> > > not sure why.  I think you're aiming for the fact that this is just a default;
> > > one can still change the ACL to anything, including to the old default.  If
> > > these notes are going to mention the old default like they do so far, I think
> > > they should also urge readers to understand
> > > https://www.postgresql.org/docs/devel/ddl-schemas.html#DDL-SCHEMAS-PATTERNS
> > > before returning to the old default.  What do you think?
> > 
> > Agreed, the new text is:
> > 
> >     Users wishing to have the former permissions will need to grant
> >     <literal>CREATE</literal> permission for <literal>PUBLIC</literal> on
> >     the <literal>public</literal> schema; this change can be made on
> >     <literal>template1</literal> to cause all new databases to have these
> >     permissions.
> 
> What do you think about the "should also urge readers ..." part of my message?

I see your point, that there is no indication of why you might not want
to restore the old permissions.  I created the attached patch which
makes two additions to clarify this.

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

  Indecision is a decision.  Inaction is an action.  Mark Batterson