It has been a while since I’ve wrote my last post about db4o. You may remember the post about the activation-mechanism. Don’t you think that this is quite painful? Activating objects with the right activation depth and so forth? Wouldn’t it be nice if db4o actually activates the objects as soon as you need then? [...]

So far we’ve always used a single object container. This it the simplest way to used db4o. Just open an embedded database an use it. In this post I’ll give a short introduction to the client-server-features of db4o. Handling concurrency is more challenging in a server-client scenario, therefore I also loose a few words about [...]

Today nearly every application has some concurrent parts. In a classic desktop-application some work is done in the background to keep the application responsive. In a web-application more than one request are handled concurrently. There’s no escape from the challenges of concurrent programs.  (All posts of this series: the basics, activation, object-identity, transactions, persistent classes, [...]

So I showed the basics, explained the activation-system and pointed out how db4o manages object-identities. So far so good, but I’ve never explain a very important feature of most databases, the transactions. Time to catch up. (All posts of this series: the basics, activation, object-identity, transactions, persistent classes, single container concurrency, Queries in Java, C# 2.0, [...]

In the last two posts (#1, #2) we never ever used anything like an id for any object. So how the hell does db4o identify objects? How does it ensure that existing object are updated? (All posts of this series: the basics, activation, object-identity, transactions, persistent classes, single container concurrency, Queries in Java, C# 2.0, [...]

Activation is a very basic concept in db4o. In this post I’ll illustrate what it is, why it’s there and how you handle it. (All posts of this series: the basics, activation, object-identity, transactions, persistent classes, single container concurrency, Queries in Java, C# 2.0, client-server concurrency, transparent persistence, adhoc query tools) The Mysterious Null-Pointer Let’s [...]

With this post I start a little series about db4o, an object database. Why? Because I think object databases are a quite unknown technology. Normally when developers talk about databases they mean a relational database. Yes, relational databases are awesome and well known. But there are lots of alternatives out there! Sadly, lots of developer [...]