Use PersistentNamespaceAttribute to designate all the classes inside a namespace to be persisted inside the database. When this attribute is applied to an assembly, it marks only the classes inside that assembly as persistent. Classes in the specified namespace but in different assemblies will not be treated as persistent. The PersistentNamespaceAttribute offers just one property - Namespace, which is used to designate the namespace that is marked as persistent.
In the following example the PersistentNamespaceAttribute attribute is used to mark that the "Foo" namespace contains persistent capable classes.
The PersistentNamespaceAttribute is one of the most important attributes. Its purpose is to mark an entire namespace as a persistent in an assembly. Without that attribute the Telerik Data Access engine won't search for persistent type in an assembly as it is highly error-prone. It should be mostly used in class library projects, which contain only persistent classes. Also multiple instances of that attribute could be specified to mark more than one namespace in an assembly as persistent.