As a DBA, sometime we will get high load alert, usually a sudden load spike. After you take several minutes to login to the system, you will see that the load is quiet, when you want to find out the root cause of the load spike, it becomes very difficult without the performance history data, and we cannot make our customers happy in this case. So I am keeping writing an utility to track the Oracle performance data for this case.
Finally I wrote a tool named "oramon", run as a background job at Oracle server side, capture some critical performance data at given interval, and write the data to several text files. And another tool (scanomon) to load some of the performance data into the performance database, and display them into different business charts with WebChart for further digg. How does it work?
All the data is carefully choosed by experience, we will get the same output under Oracle 8i/9i/10g/11g, just focus on the same performance data even on different Oracle versions. And we can customize the data display by WebChart utility. It's really hard to customize the display if you are using Oracle enterprise manager.
The most important is we can get the root cause when we hit performance problem by analyze the history data gathered, which make oramon valuable.