Dmitry Tkach <dmitry@openratings.com> writes:
> The problem is that in the 'real life' situation the condition is a lot
> more complicated than this simple is null test... I hate having to
> duplicate it, and I hate even more having to evaluate it twice on every
> insert :-(
Why evaluate it twice? The DO INSTEAD NOTHING rule should be
unconditional.
regards, tom lane