ORA-01998

This was tested on Oracle 11.2.0.2.7. I wondered what would happen if you tried to revoke SYSDBA or SYSOPER from SYS so I decided to try it out: 

SQL> revoke sysdba from sys;

revoke sysdba from sys

*

ERROR at line 1:

ORA-01998: REVOKE failed: user SYS always has SYSOPER

and SYSDBA

SQL> revoke sysoper from sys;

revoke sysoper from sys

*

ERROR at line 1:

ORA-01998: REVOKE failed: user SYS always has SYSOPER

and SYSDBA

SQL>