I created a simple utility to monitor and administrate Oracle Databases about 2 years ago. It’s called GOAT (GOAT Oracle Administration Tool). It’s more suitable for monitoring than administrating, but I haven’t changed its name, because I liked that recursive acronym.
GOAT was designed to monitor Oracle 10g and higher databases so I used ASH (active session history) views while drawing performance graphics. In my current company, we have Oracle 9.2 databases. Although we use Enterprise Manager Grid Control to monitor and manage them, I decided to bring my old utility back to life and add support for Oracle 9i.
Unfortunately Oracle 9i doesn’t support ASH, so it forced me to find an alternative. I’ve found S-ASH project created by Kyle Hailey and maintained by Marcin Przepiorowski: http://ashmasters.com/ash-simulation/