ABSTRACT
Database administrators (DBAs) need to know how to describe real-world objects and their relationships in a form that is both practical and meaningful to the database user and still be efficiently usable by the database management system. This chapter describes four conceptual database design languages from several perspectives and in sufficient detail so that a DBA, who must know the strengths and weaknesses of each design language, can use them to construct a conceptual schema that meets the needs of the database user. A conceptual database design language (CDDL) is a high-level language used by a DBA to describe a conceptual schema. The chapter evaluates the following four design languages: English, or other natural languages, Entity-relationship diagrams, SQL, and Relational diagrams. There are many other CDDLs, including the Universal Model Language and Bachman diagrams. But these four languages are the most popular with users of relational database management systems.
