Re: Database design, Keys and some other things

In the relational database, relations usually have more than an attribute and keys are not restricted to one attribute. In the "Real World" policemen do integrity checking in addition to identity checking. Also a database need to be kept updated. etc.

"vldm10" <vldm10_at_yahoo.com> wrote in message news:1127942552.091012.145730_at_g49g2000cwa.googlegroups.com...
> I would like to use your valuable input about the industry-standard,
> externally verifiable keys, to add more about identifying an entity in
> the Real World.
> Let me start with policemen who check the picture on a driver license
> and then licenceID and plate number, name etc. This is an example of
> using knowledge of more attributes rather then simple identification by
> one attribute. We can observe that the license's picture should be
> changed periodically. Same case with a passport, a membership card etc.
> And I believe that identifying by the picture and by a non key
> attributes (and new technologies) will have significant role in future.
> Second example is checking by the phone. If it is about credit card
> they ask for last four digits and other additional information. Often
> these phone identifications start with information about names,
> address, and mother's maiden name or last for digits of the ssn.
> That was the reason why I didn't define that key identifies entity in
> the Real World.
> I wrote that key provides identification. In the discussion I used the
> terms 'key helps identification' or 'key together with other
> attributes provides' identification of the entity in the Real World.
> Finally we also have to identify the relationships in the Real World.
> Many relationships are widely checked, by more then one attribute.
> Once again I appreciate your input and my input is addition to this
> important subject.
>
> Vladimir Odrljin
>
Received on Thu Sep 29 2005 - 08:57:47 CEST