I recently saw that the DBA role is missing from one of our databases and the connect privileges are revoked from almost all schemas in the database. I tried investing about how this. Initially I went to check the dba_audit_trail,unfortunately it's empty. Secondly I tried using log miner to analyse redo logs for last 5 days in short intervals. Analysing from V$LOGMNR_CONTENTS using a "DROP" filter on operation column,but still couldn't get anything. Can anyone suggest any other way to investigate this.