Back to Newsletter Archive
U P C O M I N G E V E N T S W I T H d b 4 o [more]
Wednesday, October 4, 2006 - 11:00am-12:00pm - Aarhus, Denmark
JAOO Conference : Presentation : Data persistence options in .NET
Sunday, October 22, 2006 - 9:00-10:30am - Mississauga, ON, Canada
NFJS Greater Toronto Software Symposium : Tutorial : Essential db4o
Tuesday, October 24, 2006 - 10:30am-12:00pm - Portland, OR, United States
OOPSLA 2006 : Panel : Objects and Databases - State of the Union in 2006
Wednesday, October 25, 2006 - 2:00-3:30pm - San Mateo, CA, United States
db4objects : Tutorial : Essential db4o
K U D O O F T H E M O N T H
db4o was selected "Best Innovation in .NET Technology in 2006" by readers of Germany's #1 .NET Magazine.
A R T I C L E S
-- V5.7 WITH B-TREE FIELD INDEXES FOR BLAZING FAST QUERIES --
db4o 5.7 has been released as a development version in the db4o Download Center, featuring B-tree field indexes to provide blazing fast query times. Initial test results have shown improvements of up to 200x in certain scenarios, most notably in OR queries. Also, commits on small changes are much faster and memory consumption for commits and queries is much lower.
B-trees are optimized for scenarios when part or all of a data set is on secondary storage such as a hard disk, since disk accesses are extremely expensive operations. B-trees minimize the number of disk accesses required to find data by traversing a sorted tree structure and only need a single disk access per level of the tree.
Here are some highlights from the respective Pole Position benchmarks, which are discussed in more detail on the Product News Blog:
- OR Query on 100,000 Objects went from 70secs. (v5.5) to 350ms. -- 200 times faster!
- When adding a single object to an existing set of 100,000 objects, commit time went from 2.1 seconds to 300 ms
You can start using B-Tree indexes in v5.7 with a single line of code to create an index on a field of a class:
Db4o.configure().objectClass(Car.class).objectField("pilot").indexed(true);
If you are already using field indexes, they will be automatically recreated the next time you start your application with the db4o v5.7 engine.
B-trees are another important step on our roadmap towards ever faster performance. Additional performance enhancements will include lazy query processing on B-tree ranges (COR-209) and concurrent query execution (COR-182), which will come together with further memory optimizations (to match v5.5 production release levels) as the B-tree index feature heads towards a production rollout later this year.
-- REVIEW RELEASE FOR ObjectManager 2.0 AVAILABLE NOW --
ObjectManager 2.0 Preview Release 1 is now available and can be launched with one click from your browser with Java Web Start.
ObjectManager is a Swing based GUI which allows you to easily see what's inside your database and to query and manipulate your data. The new version is a total rewrite which reflects many user requests such as:
- Powerful ad-hoc queriesEfficient handling of large data sets
- Table view for quick scrolling through large data sets
- Tree view for drilling down through an object graph
- Access to internal database information including stored classes, data size and indexes
- Management functions including Backup and Defragment
- Java Web Start support so you will always have the latest version
- Supports Java and .NET db4o database files
Please provide your feedback for this preview release in the User Forums and check the ObjectManager Wiki for release notes and other information.
-- db4o USER GROUPS --
Tokyo's db4o User Group has been the pioneer, and now China follows suit -- and perhaps you would like to start a User Group in your region, too? db4o User Groups (dUG) are grassroots organized, informal get- togethers where beginner and advance users meet and exchange their experiences with db4o.
The Japanese chapter has held 4 events in Tokyo since April 2006. At the last meeting, there were several user presentations on financial applications with db4o, including a session by Susumu Murakawa from Nomura Securities, who reported on "db4o & Derivatives Systems". Most slides are available for download from the Open User Groups folder in the db4o Download Center, and some visual impressions can be found on photos4objects. The next meeting is scheduled for 9/28 at 7-9pm in Tokyo (Event URL here).
In China, the first db4o User Group meeting will be held in Shenzhen on 10/14. Don't miss this historic event if you are in the region! Check out the event URL for more details.
Company User Groups
In addition, db4objects initiated the formation of virtual company user groups. A company user group provides an information exchange between db4o community members who are affiliated with the same company or group. To get started, we have picked the following companies with many identifiable db4o users: CSC, Deutsche Telekom, Hewlett-Packard, IBM, Intel, LogicaCMG, Siemens, UBS, and Vodafone. More information here.
Non-db4o User Groups
db4o is also a popular topic in non-db4o user groups, such as those for Java, .NET, or Linux. In New York, for instance, Jim Leotta will inaugurate Google's new offices in New York with a talk on db4o at the New York Java User Group meeting on 10/18 (Event URL here).
Sean McCormack's talk at the Wisconsin .NET User Group is already available for download from the Open User Groups folder in the db4o Download Center.
If you want to learn more about user groups, organize a local dUG chapter, join a company user group, or speak at your favorite non-db4o user group about db4o - please let us know at community@db4o.com. We're happy to provide assistance, content, publicity and give-aways!
-- REDHAT'S FEDORA LINUX NOW OFFICIALLY INCLUDES db4o --
Thanks to community member Paul Johnson db4o is now part of the Official Fedora Extras distribution, one of the most popular Linux packages.
Please visit the db4o/Fedora project Wiki for more details.
L O O K I N G I N T O T H E M I R R O R
Press coverage about db4o since the last newsletter:
"The Microsoft LINQ Project"
dot.net Magazin, September 2006, by Stefan Edlich (In German)
"db4o open source object database v 5.5 released"
TheServerSide.com, August 18, 2006, by Carl Rosenberger
--------
With best regards
The db4objects team.
www.db4o.com
newsletter@db4o.com
Phone +1 (650) 577-2340
1900 S Norfolk Street, Suite 350
San Mateo, CA 94403 (USA)