Re: RLS Design

Robert,

On Friday, July 11, 2014, Robert Haas <robertmhaas@gmail.com> wrote:

On Fri, Jul 11, 2014 at 4:55 AM, Stephen Frost <sfrost@snowman.net> wrote:
> My feeling at the moment is that having them be per-table makes sense and
> we'd still have flexibility to change later if we had some compelling reason
> to do so.

I don't think you can really change it later.  If policies are
per-table, then you could have a policy p1 on table t1 and also on
table t2; if they become global objects, then you can't have p1 in two
places.  I hope I'm not beating a dead horse here, but changing syntax
after it's been released is very, very hard.

Fair enough. My thinking was we'd come up with a way to map them (eg: table_policy), but I do agree that changing it later would really suck and having them be per-table makes a lot of sense. 

But that's not an argument against doing it this way; I think
per-table policies are probably simpler and better here.  It means,
for example, that policies need not have their own permissions and
ownership structure - they're part of the table, just like a
constraint, trigger, or rule, and the table owner's permissions
control.  I like that, and I think our users will, too.