Re: Review of Row Level Security

On Thu, Dec 20, 2012 at 4:50 PM, Kevin Grittner <kgrittn@mail.com> wrote:
> I don't think I like ALTER TABLE as a syntax for row level
> security. How about using existing GRANT syntax but allowing a
> WHERE clause? That seems more natural to me, and it would make it
> easy to apply the same conditions to multiple types of operations
> when desired, but use different expressions when desired. Without
> having spent a lot of time pondering it, I think that if row level
> SELECT permissions exist, they would need to be met on the OLD
> tuple to allow DELETE or UPDATE, and UPDATE row level permissions
> would be applied to the NEW tuple.

This gets thorny if a role inherits from multiple roles each having a
different RLS predicate.  You can OR them together, but performance
will likely suck.  I initially thought of this as well, but I think
it's just too ugly to live.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company