I wrote:
> This is uncomfortably much in bed with the tuple table slot code,
> perhaps, but I don't see a way to do it more cleanly unless we want
> to add some new provisions to that API. Andres, do you have any
> thoughts about that?
Oh! After nosing around a bit more I remembered systable_recheck_tuple,
which is meant for exactly this purpose. So v4 attached.
regards, tom lane