RESETLOGS | NORESETLOGS ========================
This clause determines whether Oracle Database resets the current log sequence number to 1, archives any unarchived logs (including the current log), and discards any redo information that was not applied during recovery, ensuring that it will never be applied. Oracle Database uses NORESETLOGS automatically except in the following specific situations, which require a setting for this clause:
You must specify RESETLOGS:
1.After performing incomplete media recovery or media recovery using a backup controlfile
2.After a previous OPEN RESETLOGS operation that did not complete
3.After a FLASHBACK DATABASE operation
If a created controlfile is mounted, then you must specify RESETLOGS if the online logs are lost, or you must specify NORESETLOGS if they are not lost. So, the point is that if we restored the controlfile backup, we have to do OPEN RESETLOGS because the controlfile type will be BACKUP controlfile. Moreover, online redo logs backups should also be available as RMAN doesn't backup online redo logs.
In order to avoid RESETLOGS, the following steps can be followed: