What is the primary key in an Ontology object type?

• A. The unique identifier for objects of a type that maps to a column in the backing dataset.
• B. A generated random string that is not tied to the dataset.
• C. A label used for user interface display.
• D. A timestamp indicating when the object was created.

Answer: (A)

In an Ontology object type, the primary key serves as the unique identifier for each object instance and it maps to a column in the backing dataset. This means every object has a stable value in that key that corresponds to a specific row in the underlying data, enabling reliable identification, joins, and data lineage across the model. A generated random string wouldn’t align with the dataset’s rows, so it couldn’t consistently identify records. A label is only for display and isn’t guaranteed to be unique or stable. A timestamp captures when something was created, not a persistent identity. The dataset-backed, unique identifier approach is what makes the primary key the correct concept here.