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_at_pluto.downsfam.net>
>
> 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?
Date: Tue, 16 May 2006 14:48:34 -0400
Message-Id: <mdjpj3-ojm.ln1_at_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_at_(Sec)ure(Dat)a(.com)Received on Tue May 16 2006 - 20:48:34 CEST