Re: New default role- 'pg_read_all_data'

Greetings,

* Magnus Hagander (magnus(at)hagander(dot)net) wrote:
> On Fri, Aug 28, 2020 at 2:38 PM Stephen Frost <sfrost(at)snowman(dot)net> wrote:
> > * Magnus Hagander (magnus(at)hagander(dot)net) wrote:
> > > Without having actually looked at the code, definite +1 for this feature.
> > > It's much requested...
> >
> > Thanks.
> >
> > > But, should we also have a pg_write_all_data to go along with it?
> >
> > Perhaps, but could certainly be a different patch, and it'd need to be
> > better defined, it seems to me... read_all is pretty straight-forward
> > (the general goal being "make pg_dumpall/pg_dump work"), what would
> > write mean? INSERT? DELETE? TRUNCATE? ALTER TABLE? System catalogs?
>
> Well, it's pg_write_all_*data*, so it certainly wouldn't be alter table or
> system catalogs.
>
> I'd say insert/update/delete yes.
>
> TRUNCATE is always an outlier.Given it's generally classified as DDL, I
> wouldn't include it.

Alright, that seems like it'd be pretty easy. We already have a check
in pg_class_aclmask to disallow modification of system catalogs w/o
being a superuser, so we should be alright to add a similar check for
insert/update/delete just below where I added the SELECT check.

> > Doesn't seem like you could just declare it to be 'allow pg_restore'
> > either, as that might include creating untrusted functions, et al.
>
> No definitely not. That wouldn't be the usecase at all :)

Good. :)

> (and fwiw to me the main use case for read_all_data also isn't pg_dump,
> because most people using pg_dump are already db owner or higher in my
> experience. But it is nice that it helps with that too)

Glad to have confirmation that there's other use-cases this helps with.

I'll post an updated patch with that added in a day or two.

Thanks,

Stephen