db4o Developer Community

As of today, db4objects releases its Eclipse based Java to C# source code conversion tool ''sharpen'' as free software.sharpen is the ''secret sauce'' that enables us to provide the [db4o object database engine] in native versions for the Java and .NET platforms from a single code base. Features include: mapping between Java and .NET native ...

As of Today our so far internal java to c# conversion utility, sharpen, is being released as free software. As an example of its usage we're going to write a simple contact management application in java and convert it to c#. While it is possible to use sharpen to convert a complete application it is advisable to handle this as an iterative ...

In this post Rodrigo introduced the concept of Transparent Persistence that makes developers life even easier as, once configured, db4o will take care of changed objects and make sure they are updated in the database (when the transaction gets committed) without developer assistance.This level of transparency is, of course, a welcome addition but ...

Hi, I've got an architecture of:     ASP.NET2 -> C# -> (ikvm) -> Java -> db4o and recently started seing a big performace hit as the number of objects grew.  As i attempt to extract 259 object I end up with about 21 million calls to System.WeakReference.get_Target() (under instantiatDeclaredFields -> ...

After one week I'm back to work. But I still don't know how to solve my problem. I would appreciate it, if someone could provide some demo code. Thanks in advance.

Good news for everybody who loves to be on the bleeding edge but hates fighting with SVN, Ant and other infrastructure tools to roll a build of their own: We have set up CruiseControl to provide fresh snapshots of the current SVN state every few hours. They are available for download here. The generated files currently include db4o core for ...

When we review db4o applications we almost always find possibilities how to improve performance with one or two db4o configuration calls. In some cases it is possible that the db4o engine itself gives helpful suggestions (''This query is not running against an indexed field.''). We have developed a new feature for this purpose, we call it ...

Because of an incompatibility with our new marshalling format, we decided to drop the old encryption mechanism: Db4o.configure().encrypt(boolean flag) Db4o.configure().password(String password) The underlying functionality is from ancient db4o times and not completely safe against intrusion. In the meanwhile we supply an excellent new safe and ...

Another bastion fell few days ago. Rodrigo managed to switch our SCM from the good old' CVS to a fresh new SVN. As far as we can tell, everything went smoothly thanks to the cvs2svn script developed by the SVN folks. If you were used to checkout the sources from our CVS, be sure to read the Source Code Access page to migrate. Isn't it ...

You may have read the blog posts about BTrees, and the new marshallers for strings and untyped references. Here is the big picture: http://www.db4o.com/downloads/db4oPolePosition.pdf The above Poleposition results document the recent progress in performance very well. The db4o versions in the PDF are a bit hard to understand. Here is the ...