SQL> select CURRENT SERVER as DBNAME from SYSIBM.SYSDUMMY1
DBNAME
ED1

SQL> select NAME as DBNAME from V$DATABASE;
DBNAME
---------
TEST

1> select DB_NAME() as DBNAME
2> go
DBNAME
-------------------------
master

db2 => LIST APPLICATIONS FOR DATABASE ED1
Auth Id  Application    Appl.      Application Id                                                 DB       # of
         Name           Handle                                                                    Name    Agents
-------- -------------- ---------- -------------------------------------------------------------- -------- -----
...
DB2      db2jcc_applica 8791       10.44.14.76.4692.110125143835                                  ED1      1
...
db2 => FORCE APPLICATION (8791) MODE ASYNC
DB20000I  The FORCE APPLICATION command completed successfully.
DB21024I  This command is asynchronous and may not be effective immediately.

SQL> select SID,SERIAL#,USERNAME,STATUS from V$SESSION where USERNAME='AJPOWELL';
       SID    SERIAL# USERNAME                       STATUS
---------- ---------- ------------------------------ --------
      1588         69 AJPOWELL                       ACTIVE
      1606        645 AJPOWELL                       ACTIVE

SQL> ALTER SYSTEM KILL SESSION '1588,69';

System altered.

SQL> select SID,SERIAL#,USERNAME,STATUS from V$SESSION where USERNAME='AJPOWELL';
       SID    SERIAL# USERNAME                       STATUS
---------- ---------- ------------------------------ --------
      1588         69 AJPOWELL                       KILLED
      1606        645 AJPOWELL                       ACTIVE

-- The killed session should receive an error, e.g.
SQL> select SID,SERIAL#,USERNAME,STATUS from V$SESSION where USERNAME='AJPOWELL';
select SID,SERIAL#,USERNAME,STATUS from V$SESSION where USERNAME='AJPOWELL';
*
ERROR at line 1:
ORA-00028: your session has been killed

ERROR:
ORA-01012: not logged on
Process ID: 0
Session ID: 1588 Serial number: 69

sp_who2 edited as it's quite wide.

1> exec sp_who2
2> go
SPID ... Command
---- ... -----------
58   ... SELECT INTO
1> KILL 58
2> go
   -- Check progress of kill
1> KILL 58 WITH STATUSONLY
2> go
Msg 6106, Level 16, State 1, Server WG0036, Line 1
Process ID 58 is not an active process ID.

SQL>

SQL>

1>