he session can be killed at the Database layer, however the Siebel object manager's DB Connector will automatically perform a session reconnect :

Here is the session from Oracle's v$session table :

The columns are; logon_time, username, sid, serial#, osuser, program, process

02/26/2014 22:29:30 SADMIN 54 173 NT AUTHORITY\SYSTEM siebmtshmw.exe 5496:6032

Kill this session :

SQL> alter system kill session '54,173,@1' immediate;

System altered.

Immediately, the DB connector calls reconnect and the session continues to run, using the same SID (54 in this case) :

02/26/2014 22:31:29 SADMIN 54 175 NT AUTHORITY\SYSTEM siebmtshmw.exe 5496:6032

Therefore the user session will persist for the user.

This reconnect feature is present, to help in situations such as;

- temporary loss of connectivity of the database for all users
- temporary network connectivity problem for a single user

So that the Siebel sessions are maintained.