Re: Proposal: 6NF

From: paul c <toledobythesea_at_dbms.yuc>
Date: Wed, 18 Oct 2006 20:40:42 GMT
Message-ID: <ejwZg.157085$5R2.155879@pd7urf3no>

David Cressey wrote:
> ...

>> PMFJI, when it comes to a dbms engine, I don't know the difference
>> between a type and a domain.
>>

> In the context of a dbms engine, a type would be the built in datatypes
> that the engine supports, like INTGER, DECIMAL, CHAR, and DATE, and also
> the builtin functions and operations, like "+" or "weekday(x)".
>
> A domain would be what you get when you say CREATE DOMAIN. It's a set, but
> it has no functions and operations other than the ones it inherits from the
> data type it is based on.
>
> Does this make sense?
>

Ièd say YOU make sense, but IT doesnèt. However, if the difference you mention is typical usage, I guess Ièll have to accept it. I vaguely remember using something like CREATE DOMAIN in SQL, perhaps that is exactly what I used, and being disappointed - I seemed no more than a name aliasing operator.

p Received on Wed Oct 18 2006 - 15:40:42 CDT