from "Selective Persistence in db4o"
"Recently I decided to swap out part of my persistence layer to db4o. This was easy since my persistence design uses the Repository Pattern and the repositories take a service into their constructors. In the example below, all I had to do was create a new db4o-backed implementation ofInstrumentServer.My experience so far with db4o - it feels very lightweight and easy to configure."
"...But for my app,I need to access,update and query the dictionary at very rapid rate..Serializing and deserializing ,again and again is just Impossible in my app.So, I am choosing a better option, a light ,easy but powerful database..And the only database that comes to my mind for this is db4o......It's the easiest yet powerful Object Oriented Database and is Open Source too. With just 2 lines, you can store an object"
http://geekswithblogs.net/sonam/archive/2008/12/09/storing-a-dictionary-in-a-file.aspx
"I've been using DB4O a lot over the last few months and I really like it. The tutorials are very easy and getting up to speed is no problem at all"
http://blog.wekeroad.com/blog/crazy-talk-reducing-orm-friction/