I remember seeing this hidden parameter in the past (11.2.0.3) and that had an issue when querying v$temp_extent_map view.This view returned wrong results if this parameter was set to true.Now is a different story in 12.1.0.2.We started to see many ORA-600 [kkqcscpopnWithMap: 0] errors.Turns out is because of the same parameter.MOS note “Query Errors With ORA-600 [kkqcscpopnWithMap: 0] (Doc ID 2260457.1)" gives a workaround and a patch to be applied.After applying the patch no more errors in the alert log.