Derive a Polyglot model with supertype groups

The previous page showed where to set the materialization strategy of a supertype group, and what each strategy means.  This page covers the derive operation itself: the dialog, and how you choose which entities reach the target physical data model.

Derive dialog hint

When you derive from a Polyglot model with supertype groups, Hackolade Studio display a hint in the dialog:

 

 

This is a  reminder that the supertype groups are derived too, following the materialization set in the Polyglot model.  When no strategy is set, the default of the target applies, and completeness and exclusivity can change the result. 

 

Select what to derive

Let's take the Vehicle supertype group, with Vehicle as its supertype and Car, Truck and Motorcycle as its subtypes.  Car is itself the supertype of the Propulsion group, with Combustion car and Electric car as its subtypes.

 

 

When you derive from Polyglot and select the parent Polyglot data model, you are presented with a selection dialog.  Under Polyglot objects to derive, the tree lists the entities of the model, including subtypes shown under their supertype.

 

By default everything in the Polyglot model to derive from is pre-selected.  And if you're happy with that, you can just click the Apply button.

 

It is only if you want to choose a subset of the Polyglot model that you should adjust the selection, typically using multi-select with the Shift or Ctrl/Cmd button plus selection with your mouse.

 

 

 

The physical model we want in this example serves one purpose: tracking the company vehicles assigned to employees.  In our example those are cars, and the application does not care how they are powered.  So Truck, Combustion car and Electric car are not needed.

 

Undesired subtypes in the derived model can be unselected via Ctrl/Cmd + click:

 

 

The resulting derived model will only contain tables for Vehicle, Motorcycle, and Car:

 

Note: all subtypes, even if not selected for the derive operation, remain visible in the Object Browser tree.  The OB tree lists what was defined in the Polyglot model, i.e. not the selection during the derive operation.
 

Polyglot only property

An entity marked Polyglot only never reaches a derived model.  Inside a supertype group the property behaves like an entity left out of the selection.

 

Derive into another Polyglot model

Polyglot is a target like the other physical targets.  When you derive a Polyglot model into another Polyglot model, then the groups are materialized following their strategy, exactly as they would be on a relational or a document-oriented target.