Oracle paging to tables without a primary key

The common case is that a table with a primary key can be a unique form of knowledge. We are able to use the primary key and rownum mates to implement. Like what:

select scott.emp.* from scott.emp left join         (select empno id, rownum num from scott.emp) id_num         on scott.emp.empno = id_num.id where id_num.num between 5 and 10;

Suppose you encounter a table that does not have a primary key to try rowid substitution. rowID is not changed by sort or query or even update, so it can be paged using this field.

select scott.emp.* from scott.emp left join     (select rowid id, rownum num from scott.emp)  id_num     on scott.emp.rowid = id_num.id where id_num.num between 5 and 10;

Oracle paging to tables without a primary key