Relational Algebra I

The relational algebra provides the theoretical underpinnings for data retrieval from a relational database. Due to its well-defined semantics, relational algebra expressions can be extensively optimized, which is critical so that queries can be executed efficiently.

Learning Objectives

Describe the purpose of the following relational operators
- selection (\(\sigma\))
- projection (\(\pi\))
- rename (\(\rho\))
Manipulate relational data using the aforementioned operators

How to Complete this Lesson

Complete the following learning activities: (2.25–2.5 hours total)

Read “Data Retrieval From a Relational Database” in Fundamentals of Database Management Systems Chapter 5: The Relational Database Model: Introduction (15–30 minutes)
Attend the class meeting (60 minutes)
Start the schema design for the project (60 minutes)
- Create the relational schema

Resources

Relational algebra (Wikipedia)
Questions for the relational algebra (30–45 minutes)