Replace Option Impact
REPLACE should be used rarely and only after careful consideration.
Restore normally prevents accidentally overwriting a database with a
different database. If the database specified in a RESTORE statement
already exists on the current server and the specified database family
GUID differs from the database family GUID recorded in the backup set,
the database is not restored. This is an important safeguard.
The REPLACE option overrides several important safety checks that
restore normally performs. The overridden checks are as follows:
Restoring over an existing database with a backup taken of another database.
With the REPLACE option, restore allows you to overwrite an existing database with whatever database is in the backup set, even if
the specified database name differs from the database name recorded in
the backup set. This can result in accidentally overwriting a database
by a different database.
Restoring over a database using the full or bulk-logged recovery model where a tail-log backup has not been taken and the STOPAT option
is not used.
With the REPLACE option, you can lose committed work, because the log written most recently has not been backed up.
Overwriting existing files.
For example, a mistake could allow overwriting files of the wrong type, such as .xls files, or that are being used by another database
that is not online. Arbitrary data loss is possible if existing files
are overwritten, although the restored database is complete.
Best Answer
rule #1) use rman for backup, recovery and cloning of databases.
since this was a user managed backup, and you need your datafiles on a different location, there are a few things to do.
at this moment you have control_files that still refer to the original datafiles locations. They need to be redirected.
now you should be able to open your database.
If you get problems before or during mount, it is probably because of wrong dbname, db_unique_name. Set them as they were/are in prod.