Re: what are keys and surrogates?

rpost_at_pcwin518.campus.tue.nl (rpost) wrote:

[snip]

>Let's consider a minimal genealogy database: every person has a father,
>a mother, and a name, but no other attributes. Using oids we can express
>this directly as a Person relation with attributes PersonID, FatherID,
>MotherID, and Name. You and JOG are expected to complain that name

     One might not have traced ones ancestry back that far. Say you have gotten ten generations back. How do you record great-to-the-8th grandparents? You do not have data on your great-to-the-9th grandparents yet and so do not have FatherIDs and MotherIDs for your great-to-the-8th grandparents.

[snip]

Sincerely,

Gene Wirchenko

Computerese Irregular Verb Conjugation:

     I have preferences.
     You have biases.
     He/She has prejudices.