I recall a number of years ago reading about a money implementation that included different currency bases and exchange rate calculation. A quick Google search turned up
which I am not sure is the same thing, but it looks like it might be something useful in the current context. -- B
Speaking generically, I guess maybe MONEY needs to be somewhat like a TIMESTAMP. At least in PostgreSQL, a TIMESTAMP can contain a TIMEZONE. I guess a MONEY type should contain a modifier identifying the issuer of the currency (E.g. U.S. Dollar vs Canadian Dollar vs. Yen vs. Yuan vs. "precious metal").