I know that we have to use reset database to make the database to current incarnation.Please understand my Question.After i do so,my database is in different incarnation.Ok.Now i dont want all those backups whichever i have taken before,So i want to delete those backups.when i want to see all those before 1 day

RMAN>report obsolete until time 'SYSDATE-1';

The above mentioned error is generated.Then how can i delete the old backups from tape.

regards,
Vinod