db4o Developer Community

Hello, I am using db4o in a ~1000 (very complex) objects database. Queries run very very slow, so I read the ''Performance Hints'' here: http://developer.db4o.com/Resources/view.aspx/Reference/Tuning/Performance_Hints The configuration that optimizes best the performance is the following: Db4o.configure().callConstructors(true);If I use ...

I am learning db4o and like it a lot. Obviously I testing performance. And I do have a problem with the following.I am using SODA.My database contains 2 000 Products, 30 100 Customers and 300 100 Orders.An Order contains a reference to a Product instance and a Customer Instance.I have one index on Customer.LastName, Order.Amount and ...

Hi! Thanks for sharing this info. Have you tried the NonFlushingIoAdapter? Best.

We invite you to participate in the db4o performance contest which will give away 6000 USD in prizes! Basically participants will provide patches to the db4o core that impact on performance and then these modifications will be judged by the community to select the winners. In order to make the whole process easier we're providing the ...

In this session Carl and Norberto demonstrate how to get started with the 1st db4o performance contest. (Watch on-line without downloading here)

One of the requirements of my project is to keep files at certain size, which means when db file reaches its predefined limit I have to open a new one. I was thinking to use ExtClient.switchToFile(), but just discovered it's not available in local mode. Application is performance-critical, so I'm looking for the fastest possible way to do it to ...

In this session Carl and Rodrigo use the JProbe profiler to analyse how reflection impacts the read and write performance of db4o for Java. They discover that the impact is very small and find a potential area to tune activation performance. (Watch on-line without downloading here)

In this session Rodrigo and Carl write a custom reflector with direct field access to be able to test the impact of reflection calls on the performance of db4o empirically. (Watch on-line without downloading here)

Hello.  Like the other folks, I've been using db4o in Android, and I'm also a bit annoyed by the fact that you need to open and close the db connection on every new activity. I know that this is something that you cannot circumvent, unless you develop an Android service.  Moreover, the built-in Android traceview does not seem to work ...

Hi, In my life of Java development, I have used JDBC to homegrown solutions to EJB to hibernate in various projects.Currently I use hibernate in current application. As a small module, we had a requirement of displaying statistical data and Charts of various types. I had to use pure JDBC for it. Most queries look like: select count(distinct ...