> VistA architect Tom Munnecke explains, relational databases' row-and-column table requirements simply are not compatible with the large structures needed by EHR, starting with the fact that EHR records are extremely sparse (consider, for example, that the non-null entries in a single patient record constitute only a tiny fraction of the set of all possible medical diagnoses).
I don't know, but this statement sounds like mr Tom doesn't quite grasp the concept of database normalization. Like each patient would have to be a row and all diagnoses would be columns? Well it doesn't work that way.
The main feature of relational databases isn't rows and columns, it's *relations* between tables.