Wayne Schroeder <raz(at)chewies(dot)net> writes:
> IMHO, it would be good for the last_value to come back null if is_called
> is false. Don't know if that's possible or even a good idea --
It's not really very practical; among other things you'd lose the
ability to specify a START value different from MIN. Of course, if we
wanted to break backwards compatibility wholesale, we could doubtless
add a separate column for START, do away with is_called altogether in
favor of representing not-iscalled by last_value = null, etc. But I
doubt it's worth the pain of breaking clients that know the existing
definitions of these fields.
regards, tom lane