Performance Improvements

There is a performance improvement, that can be used by plug-ins (in particular it is used by the rdbconfig implementation). The config library now shares implementation config object for instantiations of all generated DAL parent classes.

Technically this becomes available due to new Configuration::subclasses() method, returning subclasses hierarchy of database classes.

Example

The class C is derived from class B, and the class B is derived from class A. User creates object c of class C, object b of class B and object a of class A using the same database object. All such objects a, b and c share the same config object (that will be read once via network in case of rdbconfig implementation).