Re: Object Class and Data Type

From: Mike Sherrill <>
Date: Mon, 05 Apr 2004 05:57:56 -0500
Message-ID: <>

On Fri, 2 Apr 2004 13:31:05 -0500, "Laconic2" <> 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
Received on Mon Apr 05 2004 - 12:57:56 CEST

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