Nifty math trick with hierarchical query

My blog has moved, the article you are looking for can be found here:
https://seanstuber.com/2012/04/19/nifty-math-trick-with-hierarchical-query/

11gR2 on OEL6? yes and no

My blog has moved, the article you are looking for can be found here:
https://seanstuber.com/2012/04/19/11gr2-on-oel6-yes-and-no/