6.830/6.814: Database Systems
Spring 2021
The reading for this lecture is:
  1. The start of Chapter 4 to end of Section 4.2.5 (pages 100-110) of Ramakrishnan and Gehrke
  2. The start of Chapter 2 to end of Section 2.6 (pages 25-46) of Ramakrishnan and Gehrke
  3. Section 3.5 (pages 75-86) of Ramakrishnan and Gehrke
  4. The start of Chapter 19 to end of Section 19.4 (pages 605-619) of Ramakrishnan and Gehrke
The first reading discusses the "relational algebra" proposed by Ted Codd, which we will discuss at the beginning of lecture.

The second two readings discuss ER modeling, which is one practical way which can be used to model a database and generate relational database schemas.

The fourth reading discusses a formal model based on the notion of functional dependencies that makes it possible to reason about whether schemas are free of anomalies that lead to operational problems in database system execution. You should focus on understanding BCNF and 3NF; we will not discuss the higher normal forms.

The relationship between these last three readings is that ER modeling generally produces relational schemas that conform to 3NF/BCNF, though this isn't strictly true (see section 19.7 for a discussion of cases when ER modeling doesn't lead to BCNF or 3NF schemas.) For those who are interested, it turns out that there are relatively straightforward algorithms for generating BCNF/3NF schemas given a collection of functional dependencies -- these are given in Sections 19.5 and 19.6 of Ramakrishnan and Gehrke, but you don't need to know these in detail.

As you read these chapters, think about and be prepared to answer the following questions in Lecture: