Re: Impossible Database Design?

From: Kenneth Downs <knode.wants.this_at_see.sigblock>
Date: Tue, 16 May 2006 14:48:34 -0400
Message-Id: <mdjpj3-ojm.ln1@pluto.downsfam.net>

Nikolai Onken wrote:

> I've ordered the book..... huh, knowledge is still not cheap in the
> days of internet and newsgroups :) ...
>
> Kenneth Downs wrote:

>> The more general case can provide various rules that
>> determine which rows exclude others, in the case of the unique
>> constraint it is simple equality, in the case of time it is interval
>> overlap.

>
> Wouldn't the problem occur when I am looking for equality on an
> 'infinite' or really long scale (do 2 functions cross each other at any
> point?) rather than interval overlap?

If i understand your question, there is no problem. Two intervals are defined by their endpoints. Simple comparison of their endpoints determines if the intervals overlap.

-- 
Kenneth Downs
Secure Data Software, Inc.
(Ken)nneth@(Sec)ure(Dat)a(.com)

Received on Tue May 16 2006 - 13:48:34 CDT