user session blocks connection

Issue for resource busy:

 grant some connect resource privileges to user.

The alter system kill session command requires two unique arguments that uniquely identify the Oracle session, the session identifier and serial number.

First you have to identify the session to be killed with alter system kill session.

The SID and SERIAL# values of the Oracle session to be killed can then be substituted and the alter system kill session command issued.

SQL> ALTER SYSTEM KILL SESSION 'sid,serial#';

Sometimes Oracle.exe is not able to kill the session immediately with the alter system kill session  command alone. Upon issuing the alter system kill session  command, the session will be ‘marked for kill'. It will then be killed as soon as possible.

In the case of a session being 'marked for kill' after issuing the alter system kill session  command and not killed immediately, the alter system kill session  command can be forced by adding the immediate keyword: