You can set the depth to which DESCRIBE will show information using SET DESCRIBE DEPTH. : Object Type « Object Oriented « Oracle PL/SQL Tutorial

SQL>
SQL>
SQL>
SQL> CREATE Or Replace TYPE AddressType AS OBJECT (
  2    street VARCHAR2(15),
  3    city   VARCHAR2(15),
  4    state  CHAR(2),
  5    zip    VARCHAR2(5)
  6  );
  7  /
SQL>
SQL> CREATE Or Replace TYPE PersonType AS OBJECT (
  2    id         NUMBER,
  3    first_name VARCHAR2(10),
  4    last_name  VARCHAR2(10),
  5    dob        DATE,
  6    phone      VARCHAR2(12),
  7    address    AddressType
  8  );
  9  /

SQL>
SQL> SET DESCRIBE DEPTH 2;
SQL> /
SQL> DESCRIBE PersonType;
 PersonType is NOT FINAL
 Name             Null?    Type

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

SQL> /
SQL>

32.1.Object Type
	32.1.1.	Creating Object Types
	32.1.2.	Object instances and initialization
	32.1.3.	Nested object
	32.1.4.	Declare a function.
	32.1.5.	The MEMBER FUNCTION clause declares the getByDate() function.
	32.1.6.	The body defines the code for the method, and a body is created using the CREATE TYPE BODY statement.
	32.1.7.	Create a synonym and a public synonym for a type
	32.1.8.	Using DESCRIBE to Get Information on Object Types
	32.1.9.	Object types with member functions
	32.1.10.	add attribute
	32.1.11.	drop attribute
	32.1.12.	Object elements are referenced by using variable.attribute and variable.method notation.
	32.1.13.	Call data type member function in PL/SQL
	32.1.14.	Call data type constructor to initialize it
	32.1.15.	You must create an instance of the object first. With object types, you cannot just start assigning values to attributes.
	32.1.16.	You can set the depth to which DESCRIBE will show information using SET DESCRIBE DEPTH.
	32.1.17.	Use objects in SQL, First, you can use object types as attributes in a traditional relational way)
	32.1.18.	Alternatively, you can create an object table.
	32.1.19.	Use Object PL/SQL
	32.1.20.	Retrieve object as a whole
	32.1.21.	Using Objects
	32.1.22.	Combine user-defined type to create new type
	32.1.23.	Use self to reference member variable
	32.1.24.	Overloading based on user defined object types.