Use the Properties view to set the transformation properties
of generalization objects before you transform a logical data model
into a physical data model.
Before you begin
Before you modify the properties of logical data model objects,
you must open a logical data model in the logical data model editor.
Procedure
To set generalization transformation properties for logical-to-physical
data model transformation:
- Select a generalization object in the Data Project Explorer,
or in a diagram.
- Click to
open the Properties view, if the view is not already open.
- Optional: On the General tab
in the Properties view, modify the Transform as property
by selecting one of the following options:
Option |
Description |
Separate table |
Select to specify that subtypes and supertypes are transformed
to separate tables. |
Roll up |
Select to specify that subtype attributes are transformed
to be contained in the supertype table. |
Roll down |
Select to specify that supertype attributes are transformed
to be contained in subtype tables. |
- Optional: On the General tab
in the Properties view, modify the Defining Attribute property
by selecting a supertype entity attribute from the from the list.
The attribute that you select is defined as a type discriminator for
the generalization. When you transform to a physical model, a typed
table is added only when no type discriminator is defined on the generalization
and the Roll Up option is selected in the Transform
as field.
- Optional: Modify the order of specializations
in a generalization hierarchy. The order of specializations
is important for roll-up denormalization of a generalization.
- Select the entity that contains the generalization object
in the Data Project Explorer, or in a diagram.
- On the Generalizations tab, modify
the order of the sub types that are contained in each generalization
object.
The next time that you transform the logical data model
using the Roll Up option, the column order that you specified is preserved
in the resulting physical data model table.
- Save the logical data model.