Dear students, 

I apologize that today the Database class cannot be held as usual. As the replacement, please download and read the materials on Relational Algebra, among others are:

1. A Quick Introduction to Relational Algebra
2. Relational Algebra. In this slides, there are some QUIZ you can practice and discuss with friends. In the next meeting we will deepen the understanding on RA as this concept is essential for easy understanding on optimal query formulation.
3. Relational Algebra
4. SQL and Relational Algebra