Re: No migration path for MONEY

Peter Eisentraut <peter_e@gmx.net> writes:
> How would the new "money" be different from "numeric"?

[ temporarily re-dons currency-trader hat... ]

What would actually be useful is a money type that carries along an
indication of which currency the amount is expressed in (not per-column
as Bruce naively suggested, but right in the datum).  This would allow
conversions to be performed between different currencies, as well as
allowing the correct decoration to be provided on output.

> If we have "money", should we have "length", "mass", and
> "temperature"?  I think not.

Physicists have found use for numeric objects that carry along an
indication of the units they're in --- in other words, not "length" etc,
but a generic "measurement" type that might tag its value as "meters" or
"kilograms" or "furlongs per fortnight".

I'm not eager to go and write such a datatype right now, but if someone
wanted to do the work I'd be in favor of adopting one.

            regards, tom lane