BAO
Be a little specific about the question. Would you like to know system_wide database activity ? or who did what and when?
To have a snapshot of your database activity and identify potential problem query v$system_event.
SQL> select * from v$system_event order by time_waited;
Hope this help
Arsene Lupain
The lie takes the elevator, the truth takes the staircase but ends up catching up with the lie.