Abstract

While Bachman's role data model is often cited, it appears that its contribution, the introduction of role types and their conception as unions of entity types that occupy the places of relationship types, has mostly been ignored. This is unfortunate since it has led to countless reinventions of the wheel, and sometimes even to regress. With this homage, the author wishes to shed some light on the natural elegance of Bachman's role concept, and to make clear why he believes that it is valid until this day.