I applied logminer to find who deleted a lot of rows in one table. View v$logmnr_contents give me details of that operation. Unfortunately, minimum supplemental logging was not active when archived redo logs were generated, and when I query v$logmnr_contents, I found columns "username" and "session_info" as "unknown".
Would be there any chance to deduce what user did that operation? Maybe using timestamp to determine what users were logged at that time? Or using column Log_ID?