Oracle Solution for Error ora-19909

ORA-19909: datafile string belongs to an orphan incarnation

What triggered the Error:

ther the specified datafile was restored from a backup that was taken during a period of time that has already been discarded by a RESETLOGS operation, or Oracle cannot identify which database incarnation the file belongs to. The alert log contains more information.

What should we do to fix it:

store a backup of this file that belongs to either the current or a prior incarnation of the database. If you are using RMAN to restore, RMAN will automatically select a correct backup.