HSQLDB Development

Background

Hypersonic SQL was an open-source all-Java database engine, first released with source in 1998. It started from a simple memory-only database but by the year 2000 and version 1.43 it had developed into a fully fledged SQL engine with an avid following.

When the Hypersonic SQL project was closed, a number of developers who were using the software for their work got together through the Internet and formed the HSQLDB Development Group. The membership covers four continents. The Group released the first version of HSQLDB (1.60) in April 2001, featuring support for SQL triggers and other enhancements. The next version (1.61) followed in July that year.

Growing interest in HSQLDB resulted in more and more enhancements and new features submitted to the project. Development continued for the next 12 months and the next version, 1.7.0, was released with major new functionality. Version 1.7.1 followed in October 2002 with further enhancements.

The work on version 1.7.2 had already started when 1.7.1 was released. This process continued until July 2004 when 1.7.2 was finally released after extensive alpha and beta testing. In this version we aimed to modularize the existing code as we added new features. In this effort, we have covered several core classes and will continue towards a fully modular code base for future versions.

Development work on 1.7.3 is being carried out now.

The Development Team

Most developers contribute to this project when they have some free time or when the projects they are working on needs a particular database feature. New developers join us from time to time and some of those who have previously made major code contributions are no-longer active due to professional commitments. The development effort is coordinated by the Maintainer to ensure continuity and to avoid duplication of effort as much as possible.

We are always looking for new developers to join our team. Anyone who contributes code or documentation is welcome to join. Please send an email to the Maintainer, Fred Toussi, fredt (at) users.sourceforge.net with your proposed enhancement or join the Developers Mailing List and post there. Archives of the list are at Developers Mailing List Archive

Help is currently needed in several areas for the future versions:

• Implementation of updatable views and result sets
• New index types and implementation of GIST
• Implementation of different levels of transaction isolation
• Design and implementation of a grammar based parser
• Tests and documentation on compiling HSQLDB for PDA and similar devices
• More extensive test framework
• Work on connectors written in C, C++ or other languages to access HSQLDB from languages other than Java

Co-ordination with Users

HSQLDB is used in (or is supported by) a large number of open source projects. We welcome direct, priority contact with developers from those projects to ensure a smooth transition to new versions. We also value contributions from all other developers who use HSQLDB in their projects. We have been able to fulfil many requests for additional features or bug fixes and will continue to give priority to what users ask for. Users who want to contribute enhancements can post the code to the Patch Tracker or alternatively discuss it in the Developers Mailing List or directly with the Maintainer.

Some Details

The hsqldb CVS module contains only the files of public releases. Ongoing development is reflected in the hsqldb-dev CVS module. Developers can all commit changes to this module.

The outline plan for the new features in version 1.7.3, as well as broader discussions on the direction of the project can be found in the Open Discussion Forum.