Thursday Jun 18, 2009
Thursday May 28, 2009
By MortazaviBlog on May 28, 2009
Kristian Waagan (of Sun's Java DB development team) has really given Java DB (Sun's distribution of Apache / Derby) a new life of its own when it comes to handling CLOBs, starting with Java DB 10.5.
Check out this thread.
Note the following testimony from David Goulden:
The performance improvements with CLOBs are dramatic. I created a record with a CLOB containing about 10 million characters using derby 10.4. The following query took over 6(!) minutes:
SELECT CONTENT FROM MESSAGES WHERE ID = 1
(CONTENT is the CLOB column.)
I then installed derby 10.5 and did a soft upgrade. The same query now takes less than three seconds!
Friday May 01, 2009
By MortazaviBlog on May 01, 2009
Thursday Apr 30, 2009
By MortazaviBlog on Apr 30, 2009
Apache Derby project is the cauldron where Sun starts the forging of Java DB, Sun's distribution of Derby and the premier Java database in the world!
Most recently, Knut Anders Hatlen, Java DB engineering and committer to the Apache Derby project, has been writing about the new features being shipped in Java DB 10.5.
It is important to know that Java DB is a project 3 years in the
making, and we're now witnessing people interested in installing this
database in hundreds of instances, in the middle tier of their
applications. Java DB is particularly unique because it can easily be
embedded with a Java application in a JVM. (Anyone who has studied Java
somewhat closely should already be completely familiar with this fact.)
You can review the derby-users list on Apache to discover the level of sophistication in the user community, or go to the derby-dev list on Apache to discover and contribute to recent ideas and development with Derby replication.
In one of his many Derby 10.5 preview blog entries, Knut describes the use of generated columns, and follows up on their usability in a particular example involving case-insensitive search.
Thursday Feb 05, 2009
By MortazaviBlog on Feb 05, 2009
There are some basic, golden rules when it comes to having a vibrant community of contributors.
The following are rules I have extracted and learned based on my experience managing and working with engineers actively involved and participating in the Apache/Derby, PostgreSQL and MySQL open-source communities. These rules are also based on extensive discussions with many folks involved with the MySQL community, with the PostgreSQL community and with the Apache/Derby (Java DB) community, over many years.
Before I go through these rules, I would like to thank Marten Mickos for having suggested some of the headings for these rules. (I originally had much longer headings for all of them.) I would also like to thank many of MySQL, PostgreSQL and Java DB colleagues, as well as to many other colleagues involved in open-source development, for having contributed to the ideas and practices behind these rules.
1.Often, this openness can span all the way from development (architectural specification, implementation design and planning, implementation, code review and walk-through) to testing, qualification and release.
2.It may be possible to move towards greater transparency over time but openness in development is often the minimum starting point.
1.It should be possible to conduct open dialog and conversation regarding any aspect of the development (and other aspects of) work.
2.When mailing lists and other archive-able communication channels (such as wikis) focused on development work are opened up, it becomes easier to conduct open dialog and conversation regarding the development work.
3.Of course, when a corporation or business concern contributes (either as a major contributor or a minor contributor) to the development of an open-source product, it is to be expected that some aspects of the development work (e.g. those related to specific customer needs) may remain obscure through mechanisms such as withholding of a customer's name.
1.It should be possible to track the fate of any contribution and have a public archive of the conversation conducted regarding that contribution—recording decisions made and various feedback loops in time for the purposes of learning and further work.
2.For this purpose, it is often sufficient to have a time record of the conversation conducted with respect to the given contribution.
3.These records can be searched to determine the fate of the contribution.
4.These records help provide a learning platform for the future contributors.
D) Setting Expectations.
1.Using available and open information, the contributor community should be able to form and entertain valid expectations regarding milestones, releases, timelines, etc.
2.Anticipating the future and related risk management helps all market participants to reduce transaction costs.
E) Small is Beautiful.
1.While it should be possible to absorb contribution of any size, emphasis should be put on absorbing smaller and incremental contributions.
2.To create mass and momentum and community and quality, it helps to encourage smaller contributions.
1.Not all contributions are equal.
Contributions are judged by whether they are well designed, fit into business roadmaps, are well documented, comply with standards, do not produce regressions in the code and improve performance.
2.Not all contributors are equal.
Contributors vary in expertise, skill and experience.
These variations give meaning to the practices and procedures of the contributor community.
1.It is clear where one needs to work.
There are enough branches or trees to serve distinctly different target groups.
2.Trees and branches are well-groomed.
Active code branches or trees are kept at a minimum set in order to keep the product roadmap and expectations coherent.
1.Contributions are added in parallel with frequent synchronization so that community participants can respond to each others' work.Parallel work leads—naturally and out of brute necessity—to modularization, better and faster integration.
1.Work is conducted in increments.
2.Each contribution does one thing.
3.Each contribution has a test case that exercises it.
1.Contributor community assets (channels of communications, forums, bug databases, etc.) are developed to improve learning by all participants and contributors.
I'd like to thank Brian Aker, Knut Anders Hatlen, Davi Arnaut, Kaj Arnö, Jorgen Austvik, Igor Babaev, Mark Callaghan, Peter Eisentraut, Sergei Golubchik, Shawn Green, Lenz Grimmer, Rick Hillegas, Stefan Hinz, Geir Hoydalsvik, Henrik Ingo, Alexey Kopytov, Mark Leith, Dmitry Lenev, Manyi Lu, Giuseppe Maxia, Paul McCullagh, Mårten Mickos, Chad Miller, Francois Orsini, Konstantin Osipov, Trudy Pelzer, Sergey Petrunia, Jay Pipes, Jeffrey Pugh, Ole Solberg, Georg Richter, Mikael Ronström, Kristian Waagan, Dag Wanvik, Monty Widenius, Jeff Wiss, and more.
Tuesday Aug 28, 2007
By MortazaviBlog on Aug 28, 2007
Java DB (Sun's distribution of Apache Derby) continues to prosper.
The potential for deployment in mobile devices and nomadic applications can be tremendous, while its ease of use and deployment continue to make it attractive in client-server modes.
- Oliver Williamson Wins the Nobel Prize in Economics
- LBL, Technology and Life
- At the Mount Whitney Summit
- More on Derby
- Advancing MySQL Open Development One Important Step Forward
- A Prize Well-Deserved
- ADO.Net Entity Framework on MySQL
- How a Differential Gear Works
- Clunkers and Financial Institutions
- Workbench 5.2 Alpha
- Adam Bosworth
- Bryan Cantrill
- David Edmondson
- Edward Felton
- Hinkmond Wong
- His Holiness, The Duke
- James C. Liu
- Lawrence Lessig
- Paul Rogers
- Philip Greenspun
- Richard Friedman
- Richard Sharples
- Roberto Chinnici
- Seyed Razavi
- Simple Signs
- Simson L. Garfinkel
- Tim Bray
- Yusuf Goolamabbas
- / Persian (فارسی)
- /Art (هنر)
- /Sun Microsystems Inc.