[Nitro] compound keys

[Tim Larson]

What is the prefered way of handling compound keys, compound
foreign keys, and compound indexes using Og?  I have read the
tutorials and looked at examples, but they all seem to only
handle simple databases like you would use to support a blog,
rather than more complex schemas such as you would find in
financial applications.

ActiveRecord also seems to have this limitation (at least
from the documentation I could find) and that is what made
me start looking at Og, to see if it addresses this scope.

--Tim Larson