David Rowley <dgrowleyml@gmail.com> writes:
> Are you worried about the costs above the join that triggers that
> coming out as NaN with that fix? It appears that's the case.
[ pokes at that... ] Yeah, it looks like nestloop cost estimation
also has some issues with inf-times-zero producing NaN; it's just
not asserting about it.
I notice there are some other ad-hoc isnan() checks scattered
about costsize.c, too. Maybe we should indeed consider fixing
clamp_row_estimate to get rid of inf (and nan too, I suppose)
so that we'd not need those. I don't recall the exact cases
that made us introduce those checks, but they were for cases
a lot more easily reachable than this one, I believe.
regards, tom lane