{表領域、データファイル}自動undo管理の設定

https://docs.oracle.com/cd/F19136_01/admin/managing-undo.html#GUID-106B56C9-CB60-4E46-86A6-BF645E9E1A7F

show parameter undo
alter system set undo_management=auto scope=spfile;
alter system set undo_retention=800;