Right, so to be clear by "filename" I did mean something like "filename the user actually cares about". Almost any database (including a filesystem) has a prim

Right, so to be clear by "filename" I did mean something like "filename the user actually cares about". Almost any database (including a filesystem) has a primary key, which can be thought of as a file-name. Filesystems are unusual in that ordinary users sometimes want to explicitly deal with the records (files) and their keys (names).