oralce 数据还原

select *
  from table1 as of timestamp to_timestamp('20130621 12:08:01', 'yyyymmdd HH24:MI:SS');


update set_apply_exam sae
   set sae.item_name =
       (select t1.item_name
          from set_apply_exam as of timestamp to_timestamp('20140415 12:08:01', 'yyyymmdd HH24:MI:SS') t1
         where t1.SET_ID = sae.SET_ID)
where sae.reserve_field_code is not null;