James,
> I am seeking, as many others are or have, to improve the performance on bulk
> loads to live systems where constraint violations may occur and filtering can
> be done more efficiently within the backend.
>
> Primarily, I'm concerned with UNIQUE violations. However, I think tackling the
> general case is the wiser action.
Alon Goldshuv on Bizgres has been working on this as well. Maybe you
could collaborate? Alon?
--Josh