In reply to rajasravan:
Using the resource_db requires that the scope (arbitrary string) for the set and get match. For trivial environments this isn’t difficult. However, for complex environments, including IP from different sources, it’s more difficult to manage. That, along with some other non-intuitive behaviors of the resource_db is why you should always just use the config_db.
I have never written a testbench that required using the resource_db and I suggest you do the same.
Good luck,
-Tom