No callbacks

.NET: Db4oFactory.Configure().Callbacks(false)

Advantage

will prevent db4o from looking for callback methods in all persistent classes on system startup.

Effect

Upon system startup, db4o will scan all persistent classes for methods with the same signature as the methods defined in com.db4o.ext.ObjectCallbacks, even if the interface is not implemented. db4o uses reflection to do so and on constrained environments this can consume quite a bit of time. If callback methods are not used by the application, callbacks can be turned off safely.

Alternate Strategies

Class configuration features are a good alternative to callbacks. The most recommended mechanism to cascade updates is:

.NET: Db4oFactory.Configure().ObjectClass("yourNamespace.yourClass").CascadeOnUpdate(true)