Restrict the session's time limit

Question

Friends ,
In my oracle database 10g server the process limit is 400 and session limit is 445 .
Look at the following v$resource_limit output :
RESOURCE_NAME CURRENT_UTILIZATION MAX_UTILIZATION INITIAL_AL LIMIT_VALU
processes |399 |400| 400| 400
sessions |406| 408| 445| 445
Now the problem is , in my database more than 100 users are added last week and for this reason my database process crosses its limit (400) . In this case , when a user tries to login then he gets error :
" SQL> conn user@PROD
Enter password:
ERROR:
ORA-12537: TNS:connection closed"
In this moment , I dont want to increase the process value and want to find out the session who are idle for last 10 minues . Is there any parameter in oracle which helps to find out the idle session ?
Also , I want to disconnect those users who are IDLE for 10 + minutes . How can I restrict this without using any profile and also not incresing the v$process value ?
Waiting for reply .. .

Answer 1

try with default profile
SQL> select resource_name,limit
  2    from dba_profiles
  3   where profile='DEFAULT' and resource_name='IDLE_TIME'
  4  /
RESOURCE_NAME                    LIMIT
IDLE_TIME                        UNLIMITED
SQL> alter profile default limit idle_time 2
  2  /
Profile altered.
SQL> select resource_name,limit
  2    from dba_profiles
  3   where profile='DEFAULT' and resource_name='IDLE_TIME'
  4  /
RESOURCE_NAME                    LIMIT
IDLE_TIME                        2Khurram