How can I kill all sessions connecting to my oracle database?

Question

I need to quickly (and forcibly) kill off all external sessions connecting to my oracle database without the supervision of and administrator.

I don't want to just lock the database and let the users quit gracefully.

How would I script this?

Answer 1

This answer is heavily influenced by a conversation here: http://www.tek-tips.com/viewthread.cfm?qid=1395151&page=3

ALTER SYSTEM ENABLE RESTRICTED SESSION;  begin          for x in (               select Sid, Serial#, machine, program               from v$session               where                   machine <> 'MyDatabaseServerName'           ) loop           execute immediate 'Alter System Kill Session '''|| x.Sid                        || ',' || x.Serial# || ''' IMMEDIATE';       end loop;   end; 

I skip killing sessions originating on the database server to avoid killing off Oracle's connections to itself.

Answer 2

As SYS:

startup force; 

Brutal, yet elegant.