dba_audit_trail: value of logoff_time is prior to timestamp (logon)
621803Feb 18 2009 — edited Feb 18 2009I created an audit trail for logon and logoff of a database.
We've noticed that, occasionally, the value of logoff_time in dba_audit_trail is prior to the value of timestamp (i.e., logon time), so that the length of time the user was logged on is a negative number.
Sometimes the difference is a single second, sometimes 7 hours (which is the offset from UTC here), or 7 hours plus/minus 1 second. These constitute more than 80% of the records with negative time - the ones with a single second difference constitute about 70%.
A colleague suggested it was related to sessions that abended or were killed, but I haven't found anything to support this. So that would be the first question - why does this happen.
The second question is what the significance of the time difference is, if any.
The database is 10.2.0.1.0.
Thanks in advance.