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

On Fri, 2025-06-13 at 13:38 +0530, Vaibhav Dalvi wrote:
> I'm writing to share an observation regarding `pg_catalog` system objects
> and their privileges during `pg_upgrade`. It's known that `pg_catalog`
> system objects are not dumped, but their privileges are. However,
> if user-created objects are placed within `pg_catalog` and their privileges
> are altered, `pg_upgrade` can fail with an "object does not exist" error.

It is not supported to create objects in pg_catalog. Don't do it.

> I believe one of the following approaches should be considered to prevent
> such failures:
>
> 1. Restrict the creation of user objects within the `pg_catalog` schema.

That's already the case:

test=# CREATE TABLE pg_catalog.new ();
ERROR: permission denied to create "pg_catalog.new"
DETAIL: System catalog modifications are currently disallowed.

Yours,
Laurenz Albe