I have searched around, but I very rarely find any mention of Ruby
with OO databases.  YAML might work as a database, but I am hoping for
something more like db4o.com's GPL database engine.

Does anyone attempt Ruby with something like db4o.com's oo database engine?

I personally think that relational storage is evil.  It was built in a
time where computers were much slower and much dumber, but we have not
gotten any smarter.  For transactional databases, it attempted to
optimize speed and CRUD functions.  For datawarehousing and business
intelligence, relational databaes serve no purpose.  Has anyone dealt
with relational star and constellation schemas for datawarehouses?  An
oo structure would suit business intelligence software much better.
Ruby on Rails only masks an underlying problem.

Reference that inspired the subject's title:
http://blogs.tedneward.com/2006/06/26/The+Vietnam+Of+Computer+Science.aspx
http://www.odbms.org/download/031.01%20Neward%20The%20Vietnam%20of%20Computer%20Science%20June%202006.PDF
(pdf from odbms.org)
Disclaimer: I am unaffiliated with Ted Neward, db4o, odbms.org, etc. etc.