Stephan,
> Well, you might be better off making a max(bool), but a not
> super-efficient version might be:
>  max(case when col then 1 else 0 end)=1
Good, I'm not just brain-dead.   I did figure out another way to do it, but if
I wrote a MAX(bool), what are the chances it would get added to the core?   I
don't see any good reason not to have one.
--
-Josh BerkusAglio Database SolutionsSan Francisco