Re: RLS Design

On Thursday, July 10, 2014, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> On Wed, Jul 9, 2014 at 2:13 AM, Stephen Frost <sfrost(at)snowman(dot)net
> <javascript:;>> wrote:
> > Yes, this would be possible (and is nearly identical to the original
> > patch, except that this includes per-role considerations), however, my
> > thinking is that it'd be simpler to work with policy names rather than
> > sets of quals, to use when mapping to roles, and they would potentially
> > be useful later for other things (eg: for setting up which policies
> > should be applied when, or which should be OR' or AND"d with other
> > policies, or having groups of policies, etc).
>
> Hmm. I guess that's reasonable. Should the policy be a per-table
> object (like rules, constraints, etc.) instead of a global object?
>
> You could do:
>
> ALTER TABLE table_name ADD POLICY policy_name (quals);
> ALTER TABLE table_name POLICY FOR role_name IS policy_name;
> ALTER TABLE table_name DROP POLICY policy_name;
>

Right, I was thinking they would be per table as they would specifically
provide a name for a set of quals, and quals are naturally table-specific.
I don't see a need to have them be global- that had been brought up before
with the notion of applications picking their policy, but we could also add
that later through another term (eg: contexts) which would then map to
policies or similar. We could even extend policies to be global by mapping
existing per-table ones to be global if we really needed to...

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.

Thanks!

Stephen