Steps to recover DB (All onlinelogs lost,no valid backup)

The Method below is to help you in the case where there is you have lost all the online logs & don't have any Valid Backup :

1.  Edit the init.ora  and add :
     _allow_resetlogs_corruption=true
 
2.  Recreate control file.


3.  Recover the database
    recover database until cancel using backup controlfile;
   
4.  Open the Database with "reset logs"
     alter database open resetlogs;

5.  Immediately Take a Backup of the DB ( Exp,EXPDP,RMAN ...)


6.  Recreate the DB from the Dump.





Note : Oracle doesn't recommends the use of _ parameters unless its suggest by My Oracle Support and here we use it to get the DB back online.
Once the DB is online Take a backup and create a New one.