The figure shows representations of the PurchaseOrder_objtab and Customer_objtab object tables. A line representing a reference connects the attribute Cust_ref of the Customer_objtab table to the PurchaseOrder_objtab table.

The figure is a graphical representation of the CREATE TABLE PurchaseOrder_objtab statement and the description of the PurchaseOrder_objtyp type that precede the figure in the text. The figure is also a graphical representation of the CREATE TABLE Customer_objtab statement (also shown in figure 9-3).