Incomplete recovery differs in several ways from complete recovery. The most important difference is that incomplete recovery requires you to open the database with the RESETLOGS option. Using this option gives the online redo logs a new timestamp and SCN, thereby eliminating the possibility of corrupting your datafiles by the application of obsolete archived redo logs.
Select to open the database with the RESETLOGS option. If you are performing a Point In Time (PIT) recovery and you select , the wizard automatically enforces the option because Oracle needs the logs to be reset.
The contains information to initialize the database and instance. It is used here when the target database is started in the mount or open state. Starting with Oracle 9i, initialization parameters can also be maintained in a binary server parameter file (SPFILE). Do not enter a parameter file name if you are using an SPFILE.