Using REF, DEREF and VALUE

SQL> create table dept of dept_t;

Table created.

SQL> create table emp (

  2  ename varchar2(100),

  3  enumber number,

  4  edept REF dept_t SCOPE IS dept);

Table created.

SQL> insert into dept values (dept_t('Home','5055 Forest Run'));

1 row created.

SQL> insert into dept values (dept_t('Work','1800 Century Blvd'))

1 row created.

SQL> select * from dept;

DNAME                           ADDRESS
------------------------------  ---------------------------------

SEE CODE DEPOT FOR FULL SCRIPTS

http://www.rampant-books.com/book_1002_oracle_tuning_definitive_reference_2nd_ed.htm