"rcolmegna@tiscali.it" <rcolmegna@tiscali.it> writes:
> I'm evaluating the option of write a PG-extension which allow the
> application to apply some per-connection filters. This filters work at
> table level and remove records which aren't allowed from a select
> result-set.
It sounds a whole lot like you're trying to re-invent this:
http://pgfoundry.org/projects/veil/
regards, tom lane