Learning relational algebra by snapping blocks

Relational algebra provides a theoretical foundation for how modern database management systems optimize and execute queries. Its main concepts are based on set theory and first order logic, which can be challenging for students to learn due to their abstract nature. This paper presents Bags, a new type of visual programming environment (inspired by Snap!) for the teaching of relational operations and data analysis. Students formulate algebraic queries by snapping together graphical blocks that represent data sets and relational operators, resulting in an interactive visualization of the underlying concepts. The outcomes of this work will not only enhance university-level database courses, but also provide an engaging computational thinking resource for K-12 teachers in content areas outside of science and engineering.