Hi Troy,

Good series! I'd like to suggest that you include a bit more "real life" stucture to the model. Just enough to make the examples more "logically" realistic.

For example, there must be attributes that would be specific to different species (dog vs. cat). Otherwise why bother modeling them as subtypes? What would be the usefullness of modeling them as subtypes if they had no distinguishing attributes? Such distinguishing attributes are crucial to the rational and usefullness for modeling a subtype.

I'm sure we could all easily think of a few more typical data modeling "patterns" that appear repeatedly in real world work and that also typically are not handled well by many developers. Another would be optional attributes.

The missing model elements actually make the example more difficult to understand, in my opinion, due to incompleteness.

Thanks,

Ken