Databases Illuminated, 4th Edition

6.5 Normalization Using Candidate Keys

In practice, database designers usually develop an initial logical model for a relational database by mapping an ER diagram or other conceptual model to a set of relations. Designers identify FDs and candidate keys during the conceptual design process. By mapping the ER diagram to a relational model using the standard mapping, the designer creates a relational model that is already well normalized. To complete the relational design process, the designer checks each relation, identifies a set of FDs for it if any exist other than the ones involving candidate keys, and normalizes it further if necessary. A well-developed set of heuristics is used to guide the normalization process based on candidate keys. ...