Re: Remove default privilege from DB

Greetings,

* David G. Johnston (david.g.johnston@gmail.com) wrote:
> On Fri, Feb 16, 2018 at 7:56 AM, Durumdara <durumdara@gmail.com> wrote:
>
> > I want to know what happened in the background.
> > I will make "negative" state if I revoke DefACL without prior grant?
>
> ​Not really following the whole thread but figured I'm comment on this
> point that confused me in the past as well.​
>
> ​Not sure if this is what you mean but there is no concept of "negative
> state" in the permissions system.  Everything starts out with no
> permissions.  Grant adds permissions and revoke un-adds granted
> permissions.​  Revoking something that doesn't exist is either a no-op or a
> warning depending on the context - either way its doesn't setup a
> "forbidden" state for the permission.

This isn't entirely correct.  Functions are the classic example where
EXECUTE to PUBLIC is part of the default and the "negative" state of
having a function where EXECUTE is REVOKE'd from PUBLIC is entirely
reasonable and even common.

Further, object owners also have a default set of privileges which can
be revoked from them, and that's true of basically all objects.

> Revoking/granting on default ACLs never affects already existing objects.

Right, to change existing ACLs one would use GRANT ON ALL or individual
GRANT statements.

Thanks!

Stephen