In my domain modeling/alternative database talk , I usually spend some time talking about taxonomy in biology. It’s a fascinating field, with a lot of interesting tangents (ligers and tigons and pluots, oh my!), but in the presentation I focus on how difficult it can be to model in a standard relational schema. I think there’s another set of lessons that people interested in databases can draw from taxonomy, however, and that’s a way of looking at how databases are related. Similarity There are two main techniques in taxonomy for classifying things. Numerical taxonomy is the practice of grouping by similarity – dogs are more similar to bears than they are to cats, so dogs and bears fall into the same suborder (Carniformia, versus Feliformia for cats). As it…