Hi Hemanth,
You can refresh the content of an existing database without having to copy the primary application server instance and to reinstall additional applications servers. The refresh can be done using either database-specific methods or the SAP standard method based on R3load/Jload.
When copying the database only, you cannot change to another database but need to perform a database-homogeneous copy.
The source system and the target system already exist.
http://service.sap.com/sap/support/notes/1709838
Regards
NK