Oracle - Removing/Cleansing duplicate table rows

Removing duplicate table rows, the columns needed in the join are those that uniquely identify a specific row

delete from
   table_name a
where
   a.rowid >
   any (select b.rowid
   from
      table_name b
   where
      a.col1 = b.col1
   and
      a.col2 = b.col2
   );