Re: Storing derived and derivable data
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Fri, 21 Apr 2006 18:48:11 GMT
Message-ID: <LN92g.63791$VV4.1192704_at_ursa-nb00s0.nbnet.nb.ca>
>>Is there database theory that includes identification of
>>
>>1. the fact that values for an attribute either were or could have been
>>derived?
>>2. how values for an attribute were derived?
>>3. how values for an attribute could have been derived?
Date: Fri, 21 Apr 2006 18:48:11 GMT
Message-ID: <LN92g.63791$VV4.1192704_at_ursa-nb00s0.nbnet.nb.ca>
David Cressey wrote:
> "dawn" <dawnwolthuis_at_gmail.com> wrote in message > news:1145622076.958951.174100_at_t31g2000cwb.googlegroups.com... >
>>Is there database theory that includes identification of
>>
>>1. the fact that values for an attribute either were or could have been
>>derived?
>>2. how values for an attribute were derived?
>>3. how values for an attribute could have been derived?
What absurd questions!
The set of every attribute that could have been derived is the set of every attribute. For every inverse function fprime(x), x could have been derived by f(fprime(x)) from fprime(x). Duh!
The whole point of logical independence, which is itself a very important principle of sound data management, is to stop forcing users to ask stupid questions like #1 and #2 above.
Do I remember correctly that this idiot claims to have some background in mathematics? Unbelievable! Received on Fri Apr 21 2006 - 20:48:11 CEST