Re: pg_upgrade fails with an error "object doesn't exist"

Hi Tom,

Should we at least restrict dumping privileges for user objects inside
pg_catalog to avoid pg_upgrade failure?

Regards,
Vaibhav

On Mon, Jun 16, 2025 at 7:11 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Daniel Gustafsson <daniel(at)yesql(dot)se> writes:
> > On 16 Jun 2025, at 09:29, Vaibhav Dalvi <vaibhav(dot)dalvi(at)enterprisedb(dot)com>
> wrote:
> >> Why can't we strictly restrict object creation in pg_catalog?
>
> > Do you have allow_system_table_mods set to ON by any chance? As Laurenz
> said,
> > such creation is already restricted, but it can be circumvented by using
> said
> > GUC (which is *not* intended for production usage).
>
> I think that setting only applies to creating or modifying *tables*,
> not functions. The point of it is to keep you from breaking the C
> code's assumptions about the layout of system catalogs.
>
> Having said that, I don't see a problem here. You're not going
> to be able to create/modify functions in pg_catalog unless you
> are superuser (or a superuser gave you permissions you shouldn't
> have). There are already a near-infinite number of ways
> for a superuser to break the system, so this one isn't making it
> detectably worse. Furthermore, there are legitimate use-cases
> for adding/changing functions there. (I recall that the old
> "adminpack" extension used to do so, for example, and there are
> probably others that still do.)
>
> regards, tom lane
>