Kill all user connected sessions

To Kill the sessions:

DECLARE -- declare variables

CURSOR c1 IS

select sid, serial# from v$session

where username='ADPE';  -- declare cursor

-- declare record variable that represents a row fetched

kill_it c1%ROWTYPE; -- declare variable with %ROWTYPE attribute

BEGIN

-- open the explicit cursor c1

OPEN c1;

LOOP

FETCH c1 INTO kill_it; -- retrieve record

EXIT WHEN c1%NOTFOUND;

BEGIN

EXECUTE IMMEDIATE 'alter system kill session '''||

kill_it.sid||', '||kill_it.serial#||'''';

END;

END LOOP;

CLOSE c1;

END;

To disconnect the sessions:

DECLARE -- declare variables
CURSOR c1 IS
select sid, serial# from v$session
where username='SSS';  -- declare cursor
-- declare record variable that represents a row fetched
kill_it c1%ROWTYPE; -- declare variable with %ROWTYPE attribute
BEGIN
-- open the explicit cursor c1
OPEN c1;
LOOP
FETCH c1 INTO kill_it; -- retrieve record
EXIT WHEN c1%NOTFOUND;
BEGIN
EXECUTE IMMEDIATE 'alter system disconnect session '''||
kill_it.sid||', '||kill_it.serial#||'''immediate';
END;
END LOOP;
CLOSE c1;
END;

Please note that disconnect is more powerful than kill.