need to know the minimal access permissions required for backup in oracle 11g

Hi,

I am looking for the minimal access permissions required for oracle 11g to take backups

So, I am trying with the SYSOPER privileges. Below are the observations

1. I have created a user and granted  sysoper privilege

SQL> select * from v$pwfile_users;

USERNAME                       SYSDB SYSOP SYSAS

------------------------------ ----- ----- -----

SYS                            TRUE  TRUE FALSE

TESTER                         TRUE  TRUE FALSE

HARITHA                        FALSE TRUE  FALSE

DUMMY                          FALSE TRUE  FALSE

        2. I am able to connect to the target database remotely from SQL*PLUS, here the output

SQL> connect "haritha/haritha@har as sysoper"

connected.

  

But when I am connecting remotely from the RMAN showing TNS issue