I wrote:
> Yeah. The problem here is that once you've created an entry in
> pg_default_acl, there is no way to make it go away.
Actually that's not true: you can get rid of it with DROP OWNED BY.
This fact is even documented in the ALTER DEFAULT PRIVILEGES manual
page:
If you wish to drop a role that has had its global default
privileges altered, it is necessary to use DROP OWNED BY first,
to get rid of the default privileges entry for the role.
Not sure if this is good enough or we need to provide some more-obvious
way of dealing with it.
regards, tom lane