The title of the post can be a bit misleading as there is no such Oracle privilege “ALTER SYSTEM KILL SESSION”, and there is just “ALTER SESSION” privilege. Nevertheless, it would be nice to have something similar.
Very often developers want to have ability to kill their own sessions, i.e. sessions started by their personal database users. Apparently it is not safe to let a non-DBA user to have a right to execute the “ALTER SYSTEM” command, so what can be done?
A sys user may create a stored procedure (sp_kill_dev_session) that will only allow killing sessions started by a given user or a set of given users. For example, we can check that the session was started by SCOTT and only in that case allow it to be killed.
CREATE OR REPLACE PROCEDURE sys.sp_kill_dev_session(p_sid NUMBER, p_serial NUMBER) AS v_user VARCHAR2(30); BEGIN SELECT MAX(username) INTO v_user FROM v$session WHERE sid = p_sid AND serial# = p_serial; IF v_user IN ('SCOTT') THEN --the list can be extended EXECUTE IMMEDIATE 'ALTER SYSTEM KILL SESSION ''' || p_sid || ',' || p_serial || ''''; ELSIF v_user IS NULL THEN RAISE_APPLICATION_ERROR(-20001,'Session has Expired or Invalid sid/serial Arguments Passed'); ELSE RAISE_APPLICATION_ERROR(-20002,'Unauthorized Attempt to Kill a Non-Dev Session has been Blocked.'); END IF; END sp_kill_dev_session; / Procedure created.
Now, all we need to do is to grant EXECUTE privilege to SCOTT:
SQL> GRANT EXECUTE ON sp_kill_dev_session TO scott; Grant succeeded.
Here is how scott can call the procedure from SQL*PLUS:
SQL> exec sys.sp_kill_dev_session(14, 26043) BEGIN sys.sp_kill_dev_session(14, 26043); END; * ERROR at line 1: ORA-20001: Session has Expired or Invalid sid/serial Arguments Passed ORA-06512: at "SYS.SP_KILL_DEV_SESSION", line 14 ORA-06512: at line 1 SQL> exec sys.sp_kill_dev_session(14, 26043) PL/SQL procedure successfully completed. SQL> exec sys.sp_kill_dev_session(18,19218) BEGIN sys.sp_kill_dev_session(18,19218); END; * ERROR at line 1: ORA-20002: Unauthorized Attempt to Kill a Non-Dev Session has been Blocked. ORA-06512: at "SYS.SP_KILL_DEV_SESSION", line 16 ORA-06512: at line 1
For more tricks and cool techniques check my book “Oracle SQL Tricks and Workarounds” for instructions.