config_db usage: base class versus derived class objects

Is it possible to  do a  uvm_config_db::set()  for an  object of derived class type  using the base class handle  and  later do a   uvm_config_db::get()  of same object  using  the derived class handle

Since  a base class handle can be used to point to a derived class object and later typecase, I thought this would work, but doesn't seem to be so.

Any  help will be appreciated?

Here is an example

class  BaseA ;

endclass

class DerivedA extends BaseA

endclass

1) Set config_db

DerivedA a1;

a1 =  DerivedA::create()

uvm_config_db#(DerivedA)::set(this, "" ,  "myobj",  a1);

2) Get config_db

BaseA  a1;

DerivedA a2;

uvm_config_db#(BaseA)::get(this, "" ,  "myobj", a1);