ORA-01555 or Alter _highthreshold_undoretention integer

hello, Setting either of this parameter will limit high value of undo retention like as ; Description: _highthreshold_undoretention integer : high threshold undo_retention in seconds connect as sysdba alter system set “_HIGHTHRESHOLD_UNDORETENTION=21600” SCOPE=spfile; you need to close and open database !! SQL> show parameter undo; NAME TYPE ———————————— ——————————– VALUE —————————— _highthreshold_undoretention integer 17200 undo_management string […]