db4o 5.2 is now available as a production release.

- We have been working hard on optimizing insert, delete and commit performance. Our results for running multiple db4o versions against the PolePosition benchmark show excellent improvements. db4o 5.2 is considerably faster than db4o 4.6, even if FlushFileBuffers is turned on with our new release and turned off with the old one.

- Quite a lot of work has also been put into the Native Query Optimization Processor to allow it to optimize many more cases. Probably the most commonly used ones are String method calls. Queries like the following will now run optimized:


C#
--------

IList <Employee> employees = db.Query <Employee>(delegate(Employee e)
{
  return e.FirstName.StartsWith("P");
});

Java
--------

List <Employee> employees = db.query(new Predicate <Employee>(){
  public boolean match(Employee e){
    return e.getFirstName().startsWith("P");
    }
});

- We have also made a new sorting interface available both for Native Queries and for SODA queries. Again we have tried to follow the standards that the programming languages provide as closely as possible. Sorting simply requires passing a standard java.util.Comparator (Java) / System.Collections.IComparer (.NET).

- Our Mono version now comes with PascalCase calling conventions. A legacy version with camelCase method names is also provided with the Mono download.

- The tutorial is provided in two new languages: Visual Basic and Japanese.

Enjoy the new version!

Our near-term roadmap available here still is valid. There will continue to be a strong focus on further performance improvements, a lot more than you would expect from the "Fast Collections" bullet point on the list.

Our 5.1 development build available in the download center area of our website finally also fully enables Native Queries on Mono.

It took us quite long to get this out because our code stumbled across a bug in the Mono compiler: It did not understand the acyclic Visitor pattern that we used in the Native Query optimizer. After changing the pattern everything works fine now and all regression tests pass.

Enjoy Native Queries!

A first development release of db4objects' new db4o Replication System (dRS) is available for download.

dRS provides bi-directional object synchronization functionality for db4o object persistence systems and Hibernate relational persistence systems.

dRS brings the best of both worlds together:
Your enterprise data can stay where it is, in your existing relational database. On your client systems you can benefit from the ease of development, the performance and the low ressource consumption of the db4o object database. Data and objects can stay perfectly in sync, whether you use db4o as a peformance cache, for partially- or for fully disconnected systems.

Here is what the dRS system does exactly:

• dRS generates Unique Universal Identifiers (UUIDs) and version numbers for all stored objects.


• Since each stored object has a unique identity, objects can be replicated in multiple steps over multiple disconnected or partially connected persistence systems.


• Version numbers allow querying for and replicating changed objects only.


• The system automatically traverses changed members of replicated objects and replicates these changed members as well.


• Conflicts (objects changed in both peers of a replication session) can be resolved using object-oriented conflict handlers and business rules of persistent classes.

Further information can be found on the dRS product sheet.

dRS is free under the GPL and available under a commercial license as well.

Please download, try it out and tell us what you think.