Data Architecture Diagram Type
Explanation
Section titled “Explanation”Data architecture describes data at several levels. Each level suits a different reader.
Conceptual level. A conceptual data model names the core business entities, the main things the business cares about. It gives few attributes, or none. People use it mainly to spot duplicated data. See Conceptual Data Model.
Logical level. A logical data model adds a primary key and attributes to each entity. A primary key is the attribute that identifies one record. The model also shows relationships. It stays purely logical: it declares business terms and concepts, not database details. See Logical Data Model.
Physical level. A physical data model is the schema for one particular database. Because it is tied to that database, it may be denormalized. That means the design departs from the clean logical structure to gain performance. This sets it apart from the logical level. See Physical Data Model, and Conceptual, Logical and Physical Data Model.
Link to TOGAF. TOGAF is an architecture framework (see TOGAF). In TOGAF, a physical data component is the vendor- or technology-specific form of a logical data component. This ties the logical and physical levels together.
A set of data diagrams can therefore start with the business view, add detail, and end with the technology-specific view.
Example
Section titled “Example”A retailer first draws a conceptual diagram with Customer, Order and Product, joined by simple relationships. The drawing shows that two teams both track Customer. A logical diagram then gives each entity attributes and a primary key, such as a customer number. A physical model finally fixes the schema for the chosen database.
Trade-offs
Section titled “Trade-offs”Each step toward the physical level adds detail and ties the design to one database. A physical model may be denormalized for performance, so it no longer mirrors the logical model exactly. Conceptual diagrams stay readable for business people but say little about attributes.
Checks
Section titled “Checks”- The conceptual data diagram names core business entities and is used to find duplicated data.
- The logical data diagram gives each entity a primary key and attributes without database-specific detail.
- Any denormalization for performance appears only in the physical, database-specific model.
- Each physical data component is traced to the logical data component it realizes.
Related
Section titled “Related”- Conceptual Data Model
- Logical Data Model
- Physical Data Model
- Conceptual, Logical and Physical Data Model
- Data Architecture Artifact
- Data Architecture
- TOGAF
- Data Entity/Data Component Catalog