Re: A Question on Integrety

On Sat, 20 Dec 2003 08:42:51 -0600, "Dawn M. Wolthuis" <dwolt_at_tincat-group.com> wrote:

>> IME, the idea never bears fruit. Bad data never becomes good data
>> without a *lot* of effort, and the effort is almost wasted when you
>> put the good data into a database where "anything goes (in)".
>>
>
>This statement seems analogous to something like "it makes no sense to make
>a draft of a paper using word processing software before finalizing it".

It might seem that way, but it's not. A draft of a paper and a published version of a paper are two different things. And that's my point. A CHAR(2) column (say) whose domain is all possible two-letter combinations is a different thing than a CHAR(2) column whose domain is the two-letter state codes governed by the USPS.

>A good implementation of a DBMS should provide similar features. As I
>understand it, in some implementations of an RDBMS (or perhaps only in
>Tutorial D) there is the ability to implement local constraints rather than
>only global constraints.

Where did you read that?

-- 
Mike Sherrill
Information Management Systems