A Model Object of type Hub can be created in the Silver Layer.
What is a Hub
In Data Vault modeling, a Hub represents a structural object. A Hub should have a set of business keys to identify a unique data entry.
Creation steps
There are two possibilities to create a Hub Model Object:
- Create a Model Object with the Wizard:
- Recommended possibility
- Use the Wizard Create a Hub from a Stage or a Stage Composite that contains the following steps:
- Create a Model Object manually:
-
- Not recommended possibility
- Create a Model Object of type Hub in the Silver Layer
- Create a Dataflow Set
- Add a Model Object to the Dataflow Set: add the Stage Model Object
- Auto-map the Source Terms: select the auto-map mode and auto-map all the Source Terms, which are defined as Business Keys in the Source Model Object
Properties
A Hub Model Object can be configured through the following Properties:
-
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 Hub 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 = {null}
- Dataflow Sets amount: min = {1}, max = {null}
- Dataflow Set Model Objects amount: min = {1}, max = {null}
- Relationships amount: min = {null}, max = {0}
- Terms amount: exclude Default Terms = {true}, exclude Business Keys = {true}, exclude Identities = {false}, exclude Foreign Keys = {false}, exclude unmapped Terms = {false}, min = {null}, max = {0}
- Supported Term Data Types: exclude Default Terms = {true}, exclude Business Keys = {false}, exclude Identities = {false}, exclude Foreign Keys = {false}, exclude unmapped Terms = {false}
- Business Key Terms amount: min = {1}, max = {null}
- Identity Terms amount: min = {1}, max = {1}
- Identity Terms not nullable
- Supported Implementation Types: supported Implementation Types = {Permanent}
- Supported Deduplication Methods: supported deduplication Methods = {None, Distinct, Partition}
- Supported Load Cachings: supported Load Cachings = {Hashing}