Set Data Type

This dialog box is used to specify the data type for a user-defined attribute. Select the category for this type (Logical, Distinct, Collection, or Structured), then select the specific type within that category.

If you specify Logical Type and click the displayed type, the Logical Type dialog box is displayed.

Reference: For a structured type, controls whether the type is created as a REF (reference). A REF is a logical pointer to a row object that is constructed from the object identifier (OID) of the referenced object and is an Oracle built-in data type. REFs and collections of REFs model associations among objects, particularly many-to-one relationships, thus reducing the need for foreign keys.