Where to hook my custom access control module?

Hello,

I'd like to look at a possibility of integrating OpenPMF
(http://www.openpmf.org) with the PostgreSQL. There is a possibility to
have a "weak" integration by using a provided rule system and SQL, but
this way we would lose central management functionality of OpenPMF,
especially its policy violation notifications and we'll need to
synchronize rules with policies from time to time. So now I think about
how to directly integrate some kind of OpenPMF policy enforcement point
into the PostgreSQL. For this I would need some access control hook inside
PostgreSQL which would be called on every action and my PEP would get a
chance to deny some access. Is there anything like that supported in the
PostgreSQL?

Thanks!
Karel
--
Karel Gardas kgardas(at)objectsecurity(dot)com
ObjectSecurity Ltd. http://www.objectsecurity.com