if we has to do complete database refresh with dump file from production to test, does we need to delete test database and recreate it and need to import..?
just confirming with you before proceeding.
Likely no one is responding to your question because no one has any idea what you've done or are trying to do: Myself included.
What does "complete database refresh" mean? Does this mean you are trying to replace SYS and SYSTEM?
What is a dump file? Does this mean something created in EXPORT or DataPump or something else?
In what version, on what operating system, how large, and why aren't you using RMAN?
If you want help you need to communicate what you are trying to do, where, and why.
Are you trying to move a database from test to production or otherwise? Is the database in archivelog mode? What version of oracle are you working with? Your answer to these questions will be helpful to determine your best option.