This article started out as a talk, Is FileMan Relational? that I’ve given on a few occasions at MUMPS and VistA conferences. File Manager (or just FileMan) is a MUMPS application that provides another level of abstraction and a set utilities that comes close to being a database management system built on top of MUMPS. In fact, I often compare the relationship between FileMan and MUMPS to the storage engines in MySQL. Without going into too much detail, I ask to what degree FileMan follows Dr. E. F. Codd’s famous twelve rules, and conclude that it compares favorably with popular relational database management systems. This meant to be counterintuitive, and a bit provocative, because the basic abstraction in FileMan (the file) has a hierarchical…