Re: Role membership and DROP

On Fri, 2019-11-15 at 13:41 -0500, Tom Lane wrote:
> Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)at> writes:
> > On Wed, 2019-11-13 at 17:17 -0500, Tom Lane wrote:
> > > It might be worth clarifying this point in section 5.7,
> > > https://www.postgresql.org/docs/devel/ddl-priv.html
> > > but let's not duplicate that in every ref/ page.
> > I have attached a proposed patch.
>
> <para>
> The right to modify or destroy an object is always the privilege of
> - the owner only.
> + the owner. Like all privileges, that right can be inherited by members of
> + the owning role.
> </para>
>
> Hm. This is more or less contradicting the original meaning of the
> existing sentence, so maybe we need to rewrite a bit more. What do
> you think of
>
> The right to modify or destroy an object is inherent in being the
> object's owner. Like all privileges, that right can be inherited by
> members of the owning role; but there is no way to grant or revoke
> it more selectively.
>
> A larger problem (pre-existing, since there's a reference to being a
> member of the owning role just a bit further down) is that I don't think
> we've defined role membership at this point, so the reader is quite
> entitled to come away more confused than they were before. It might not
> be advisable to try to cover role membership here, but we should at
> least add a cross-reference to where it's explained.

I think you are right about the potential confusion; I have added a
cross-reference. That cross-reference is hopefully still in short-term
memory when the reader proceeds to the second reference to role membership
a few sentences later.

I like your second sentence, but I think that "the right ... is inherent
in being the ... owner" is unnecessarily complicated.
Removing the "always" and "only" makes the apparent contradiction between
the sentences less jarring to me.

I won't fight about words though. Attached is my second attempt.

Yours,
Laurenz Albe