Using DESCRIBE to Get Information on Object Types

CREATE TYPE t_address AS OBJECT (
    street VARCHAR2(15),
    city VARCHAR2(15),
    state CHAR(2),
    zip VARCHAR2(5)
);
/

CREATE TYPE t_person AS OBJECT (
    id INTEGER,
    first_name VARCHAR2(10),
    last_name VARCHAR2(10),
    dob DATE,
    phone VARCHAR2(12),
    address t_address
);
/

SQL> DESCRIBE t_address
 Name                                      Null?    Type
 ----------------------------------------- -------- -------------------

 STREET                                             VARCHAR2(15)
 CITY                                               VARCHAR2(15)
 STATE                                              CHAR(2)
 ZIP                                                VARCHAR2(5)

SQL>

SQL> SET DESCRIBE DEPTH 2
SQL> DESCRIBE t_person
 Name                                      Null?    Type
 ----------------------------------------- -------- -------------------------

 ID                                                 NUMBER(38)
 FIRST_NAME                                         VARCHAR2(10)
 LAST_NAME                                          VARCHAR2(10)
 DOB                                                DATE
 PHONE                                              VARCHAR2(12)
 ADDRESS                                            T_ADDRESS
   STREET                                           VARCHAR2(15)
   CITY                                             VARCHAR2(15)
   STATE                                            CHAR(2)
   ZIP                                              VARCHAR2(5)

SQL>
SQL>