A Model Object of the type History View can be created in the Raw Vault Layer.
What is a History View
In a Data Vault model, a History View bundles the historized information of a Hub and its Satellites or a Link and its Link Satellites.
The modeler can choose which Satellites should be used.
A History View contains the following information:
- Identity and BK Terms (from the Hub/Link)
- Selected Satellite Attributes (chosen by the modeler)
Creation steps
There is one possibility to create a History View Model Object:
- Create a Model Object manually:
- Create a Model Object of type History View in the Raw Vault Layer
- Add a Model Object to the Dataflow Set: Add the PIT table, the Hub, and all the desired Satellites
- Auto-map the Source Terms: Select the auto-map mode and auto-map:
- The Hub_HK
- The Hub Business Key(s)
- The business terms of all the desired Satellite(s)
Filling the Join Expressions between the Dataflow Model Objects (PIT table, Hub, and Satellite(s)) is unnecessary. The latter can be in any order in the same Dataflow Set.
Properties
A History View Model Object doesn't propose any Property.
Default Terms
A History View Model Object will include the following Default Terms:
Business Rules
The following Business Rules are checked during the Model Object creation:
- Dataflows amount: min = {1}, max = {1}
- Dataflow Sets amount: min = {1}, max = {1}
- Dataflow Set Model Objects amount: min = {1}, max = {null}
- Relationships amount: min = {null}, max = {0}
- Terms amount: exclude Default Terms = {true}, exclude Business Keys = {false}, exclude Identities = {false}, exclude Foreign Keys = {false}, exclude unmapped Terms = {false}, min = {1}, max = {null}
- Supported Term Data Types: exclude Default Terms = {true}, exclude Business Keys = {false}, exclude Identities = {false}, exclude Foreign Keys = {false}, exclude unmapped Terms = {false}