Re: Modelling Disjoint Subtypes
Date: Sun, 25 Mar 2007 12:07:42 GMT
>>Could anyone please provide a meaningful relational design example where >>disjoint entity subtype/supertype hierarchy would truly be beneficial ? I >>am aware of Pascal's example but do not find it convincing.
> The fundamental insight is that the two (or more) entities in question
> are not
> identical, but they're not utterly unlike each other. I'm pretty sure
> makes that point.
I think the more enlightening observation is to note the end result is merely two relations. Whether one wants to consider them as a sub-anything or super-anything is more psychological than anything else. Received on Sun Mar 25 2007 - 14:07:42 CEST