Documentation has traditionally played a key role as an aid in program understanding. However, most documentation is "in-the- small," describing the program at the algorithm and data- structure level. For large, legacy software systems, one needs "in-the-large" documentation describing the high-level structural aspects of the software system's architecture from multiple perspectives. One way of producing such structural documentation for existing software systems is to use reverse-engineering technologies. This paper describes a case study in structural redocumentation: an analysis of SQL/DS (a multimillion line relational database system) using a flexible reverse-engineering approach developed as part of the Rigi project.