IDA: Partitioning a logical data model

 

If you are working on a logical data model in a team environment, there are some suggested best practices for how to partition the logical models.

The preferred method for partitioning a logical data model is by creating submodels from packages. This approach has benefits including more flexibility and better partitioning of the logical data model in a team environment so that you can avoid having to merge changes. After you create a submodel from a package, you can open and access the sub-model through a shortcut in the main model, or you can open and work with a submodel directly. Containment is maintained between the main model and the submodels so that logical-to-physical data model transformation, impact analysis, and web publishing can be run transparently from the main model.

• Creating a submodel from a package in a logical data model
  You can use the workbench to create submodels from existing packages in a logical data model. This is one way to partition a large logical data model when you are working in a team environment.
• Loading or unloading a submodel in a logical data model
  Submodels in a partitioned logical data model can either be loaded or unloaded in the main model. If a submodel is loaded, then actions such as model analysis, web publishing, or impact analysis that are performed on the main model are also automatically performed on the submodel. If a submodel is not loaded, then these actions on a main model are not performed on the submodel. You can improve modeling performance by only loading the submodels that you are currently working on.

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Creating a submodel from a package in a logical data model

You can use the workbench to create submodels from existing packages in a logical data model. This is one way to partition a large logical data model when you are working in a team environment.

Prerequisite: Before you modify a logical data model, you must open the model in the logical data model editor.

To create a submodel from a package in a logical data model:

1. Select a package in the Data Project Explorer. You can select any package except for the root package of the model.
2. Right-click the package and select Create Submodel from Package.

The submodel is created and displayed in the Data Project Explorer as a new .ldm file, with the same name as the original package. A shortcut to the submodel is displayed under the main model, and the package icon changes to indicate that the package object has been changed to a shortcut to a submodel .

 

 

Loading or unloading a submodel in a logical data model

Submodels in a partitioned logical data model can either be loaded or unloaded in the main model. If a submodel is loaded, then actions such as model analysis, web publishing, or impact analysis that are performed on the main model are also automatically performed on the submodel. If a submodel is not loaded, then these actions on a main model are not performed on the submodel. You can improve modeling performance by only loading the submodels that you are currently working on.

Prerequisite: Before you modify a logical data model, you must open the model in the logical data model editor.

You can distinguish whether a submodel is loaded by the labels on the objects. If a submodel is loaded, the label on the object in the Data Project Explorer is appended with [Loaded]. If a submodel is not loaded, the icon on the object changes and the label on the object in the Data Project Explorer is appended with [Unloaded]. A submodel can be open in another editor, but not loaded from the main model.

When you open a logical data model that contains submodels, the submodels are automatically loaded or not loaded depending on their state when the main model was last saved and closed.

To load or unload a submodel in a logical data model:

• To load an unloaded submodel, right-click it in the Data Project Explorer and select Load. The model is closed in the Data Project Explorer and the icon and label decoration changes to indicate that the object is loaded.
• To unload a loaded submodel, right-click it in the Data Project Explorer and select Unload. The model is opened in the Data Project Explorer and the icon and label decoration changes to indicate that the object is unloaded.

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