This was tested on Oracle 11.2. I had a session in the middle of a long-running operation:
SQL> conn user1/user1
SQL> conn user1/user1
Connected.
SQL> exec dbms_lock.sleep(3600);
I tried to kill it like this but Oracle gave me an ORA-00031 instead:
SQL> select sid, serial# from v$session
2 where username = 'USER1'
3 /
SID SERIAL#
---------- ----------
7 62
SQL> alter system kill session '7,62'
2 /
alter system kill session '7,62'
*
ERROR at line 1:
ORA-00031: session marked for kill
SQL>
… and the session carried on regardless:
SQL> conn user1/user1
Connected.
SQL> exec dbms_lock.sleep(3600);
I really wanted to kill it straight away so I did it like this:
SQL> alter system disconnect session '7,62'
2 immediate
3 /
System altered.
SQL>
… and the session died there and then:
SQL> exec dbms_lock.sleep(3600);
BEGIN dbms_lock.sleep(3600); END;
*
ERROR at line 1:
ORA-03113: end-of-file on communication channel
Process ID: 15294
Session ID: 7 Serial number: 62
SQL>
When I tried to carry on using it, Oracle told me I had been disconnected:
SQL> select sysdate from dual
2 /
ERROR:
ORA-03114: not connected to ORACLE
