Create a Hierarchical Link

A Model Object of type Hierarchical Link can be created in the Silver Layer.

What is a Hierarchical Link

In a Data Vault model, a Hierarchical Link is a many-to-many recursive relationship structure, housing a unique list of associations across two or more business keys at different levels of data. It represents hierarchies inside the same Hub.

Use case example

You can find a complete use-case example in the article Use parent-child relationships.

Creation steps

There are two possibilities for creating a Hierarchical Link Model Object:

Create a Model Object with the Wizard:
- Recommended possibility
- Use the Wizard Create a Hierarchical Link from a Stage or a Raw Vault Composite that contains the following steps:
  - Create Model Object
  - Create Dataflow
  - Create Relations: number = {null}
  - Map Foreign Key Terms
  - Add to View

Create a Model Object manually:
- Not recommended possibility
- Create a Model Object of type Hierarchical Link in the Silver Layer
- Create a Dataflow Set
- Add a Model Object to the Dataflow Set: add the Stage or Raw Vault Composite Model Object

- Add a Relationship to the first corresponding Hub (here, the Hub Employee)
- Edit the Foreign Key Terms: set them as Business Key
- Add a second relationship to the same Hub (here, the Hub Employee)
- Edit the Role names (See Have several Relationships to the same Model Object) with:
  - First Relationship with the Hub: Employee
  - Second Relationship with the same Hub: Manager
- Map the Foreign Key Terms: select the target mode and manually map the Foreign Key Terms to the corresponding Source Terms:
  - FK for the Role of Employee with the EmployeeBusinessEntityID
  - FK for the Role of Manager with the ManagerBusinessEntityID

In both cases, as some manager employees do not have managers, please set the FK for the Role Manager as Nullable.

Properties

A Hierarchical Link Model Object can be configured through the following Properties:

Implementation Type
Deduplication Method or Optimization Method (Only for Spark Generator)
Deduplication Partition or Optimization Method Columns (Only for Spark Generator)
File format (Only for Spark Generator)

Default Terms

A Hierarchical Link Model Object will include the following Default Terms: