JRS Home Page

JRS (Java Relational System) is a relational DBMS implemented in Java and designed for educational use

• to practice with SQL using a platform independent, lightweight system with low memory requirements,
• to practice with query plans, i.e. how the system processes queries,
• 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.

The project was coordinated by Antonio Albano and the software was developed by the following dedicated students:

• Giovanna Colucci, Emanuele Corino, 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)
• Ciro Valisena (Graphical Editors for Logical and Physical Plans)

The swing interface and the browser were implemented by Renzo Orsini. The representation of a query plan in the form of a tree was implemented by Luca Saiu. Their effort and cooperation in bringing JRS to life are much appreciated.

The choice of Java was made to simplify the implementation by several students and to have an easier-to-update and portable system.

JRS has been developed in conjunction with the text Costruire sistemi per basi di dati (available in English: Relational DBMS Internals) by Antonio Albano. The HTML documentation provides an overview of the system architecture and component interfaces. The text provides the necessary background on file organizations, buffer management, access methods, relational query languages and operator implementation techniques, query optimization, concurrency control and recovery.

JRS was inspired by similar projects made in C++ first by DeWitt and Jussi Myllymaki (Minirel) and then by Mike Carey and Raghu Ramakrishnan (Minibase) at Wisconsin University.

JRS Architecture

Versions of JRS

• Read me
• The JRS with Graphical Editors of Logical and Physical Plans, without transactions
• File to load SportDB, a database example
• HTML help files to add in the system directory

Costruire sistemi per basi di dati

October 2013