Re: Object Class and Data Type

On Fri, 2 Apr 2004 13:31:05 -0500, "Laconic2" <laconic2_at_comcast.net> wrote:

>Now, my question: does the addition of "create domain" add to the DDL
>expressiveness of SQL, and is the addition important?

I think it does add value, and I think it's important. But it could have been a lot better. You can't define operations, for one thing. (Or, more important sometimes, you can't undefine operations.)

CREATE DOMAIN prevents joins on columns of different domains. I suppose that might be product-dependent. I can't recall a product that supported CREATE DOMAIN, but allowed joins on columns based on different domains, but I wouldn't be surprised if there were one.

-- 
Mike Sherrill
Information Management Systems