The situation I am going to tell you didn't happen to me. Thank God!
I wonder, an extreme recovery case. For example, think a database in archivelog mode that we are trying to recover. The case is; redo logs are lost and archivelogs are older than five minutes before the crash. Is it possible to recover losseless?
I mean, if redo logs are not switched to archivelogs and redo logs are lost; is it possible to recover with zero data loss?