I'm a fan of RDBMS (E-R) and SQL - it's cute and all for things like purchase orders and shopping carts and orders and receipts and the like. But for things lik

I'm a fan of RDBMS (E-R) and SQL - it's cute and all for things like purchase orders and shopping carts and orders and receipts and the like. But for things like clinical informatics (even the non-semantic kind), graph traversal is easier than the unholy join from hell. For example.