Tuning Oracle SQL query

delete plan_table;

explain plan for select * from (select rownum rn, a.* from hr.countries a) where rn > 2 and rn <= 2+ 5;

select
  substr (lpad(' ', level-1) || operation || ' (' || options || ')',1,30 ) "Operation",
  object_name                                                              "Object"
from
  plan_table
start with id = 0
connect by prior id=parent_id;


delete plan_table;

explain plan for select * from (select rownum rn, a.* from hr.countries a) where rn > 2 and rownum <= 5;

select
  substr (lpad(' ', level-1) || operation || ' (' || options || ')',1,30 ) "Operation",
  object_name                                                              "Object"
from
  plan_table
start with id = 0
connect by prior id=parent_id;