Mike wrote:
>>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
> Pascal
> 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 - 07:07:42 CDT
