grab logon time

Our Management is trying to keep track of who was logged on for how long in the system. I am using v$session to get a report like this. I thought I could take the min logon-time and subtract it from max logon-time for a particular user - this will give the number of hours/min he was logged on. The problem with that is that if the person logs off for two hours and logs back on then the above method will still show him as logged on all the time - since we will still subtract the min from max.

How do we get a real picture of how long was some one logged on today.

Any suggestins will be appreciated Received on Mon Nov 01 1999 - 17:38:10 CST