There are three intertwined themes in this chapter. First, we introduce you to the design of information structures using the relational model. We shall see that. Tables of information, called “relations,” are …

Recall: Director could be stored as attribute of FILM because only one director per film assumed, but multiple characters in a film implies that ROLE must have its own relation. Each tuple in the relation …

Files belong to the physical level of data modeling. Sequential files are best for applications that access records in the order in which they are stored. Direct access (or random access) files are best when …

Describe the structure of the Relational model, and explain why it provides a simple but well-founded approach to the storage and manipulation of data. Explain basic concepts of the Relational model, …

T. Connoly, C. Begg, Database Systems, A Practical Approach to Design, Implementation, and Management, Chapter 4 The Relational Model, Pearson Education Ltd, 2015

-- 1. Review: Fundamental Concepts -- -- We want to store data in a database to get all the great features we -- discussed last lecture (an efficient way to ask all sorts of questions -- on the data, an …

Earlier models tied to physical data layout − Procedural access to data (low-level, explicit access) − Relationships stored in data (linked lists, trees, etc.)