On Fri, 2009-10-09 at 11:46 -0700, Christophe Pettus wrote:
> Domains are basically type aliases with an optional CHECK clause, so
> you could do something like:
>
> CREATE DOMAN sales_tax_rate AS DECIMAL(5,5) CHECK (VALUE >= 0);
>
> Then, you can use the type "sales_tax_rate" in your tables, etc. just
> as a normal first-class type. (The only limitation, right now, is
> that you can't create an array of them.)
Actually I wouldn't bother with the precision and scale at all. I'd go
with something like
CREATE DOMAN sales_tax_rate AS DECIMAL CHECK (VALUE >= 0 AND VALUE <=1);