About JRS

JRS is a relational DBMS implemented in Java and designed for instructional use

• to practice with the so-called SQL-92, a subset of the latest version bag-based of SQL, using a platform independent, lightweight system with low memory requirements;
• to practice with physical query plans, i.e. how the system processes queries, and with logical query plans, i.e. how the system translate queries into the relational algebra;
• to experiment the impact of alternative query optimization techniques and indexes on query plans;
• to understand how a relational DBMS works by exploring the JRS component interfaces;
• to experiment data structures and algorithms to implement database systems;
• to formulate and execute queries with a Graphical Editors to define queries with Logical Plans using relational algebra, and with Physical Plans using the JRS physical operators to define an algorithm to execute queries.

JRS design was guided by Antonio Albano and the software was developed by the following dedicated students:

• Giovanna Colucci, Patrizia Dedato (SQL Interpreter),
• Martina Filippeschi, Leonardo Candela (Query Optimization),
• Simone Marchi, Cinzia Partigliani (Query Plan Evaluator),
• Stefano Fantechi (Transaction and Concurrency Management),
• Stefano Dinelli, Marco Sbaffi (Tree Indexes),
• Lorenzo Brandimarte (Data Storage and Buffer Management),
• Luca Saiu (Graphical representation of physical query plans),
• Ciro Valisena (Graphical Editors for Logical and Physical Plans).

The swing interface and the browser were implemented by Renzo Orsini.