Re: Commit rules or Commit trigger

On Thu, Apr 27, 2006 at 10:17:51 -0400,
  Vivek Khera <vivek@khera.org> wrote:
>
> On Apr 24, 2006, at 9:37 AM, Claudio Tognolo wrote:
>
> >I am developing a temporal database and I have the necessity to
> >control the integrity constraints befor the commit of the transiction.
> >I cannot use the deferrable checking because the integrity
> >constraints is a select and i cannot use the trigger or rule because
> >the event parameter not support the commit event.
> >You have some idea?
>
> My understanding is that deferred constraints are not checked until
> commit time, which seems to be what you want.  Why do you believe
> otherwise?

But you aren't really allowed to do selects in constraints even though you
can make Postgres do that in a way that partly works. You need to enforce
these constraints with an after trigger.