Relational Database Format (RDF) VS. Unified RDF (URDF)

Below is a detailed breakdown of the differences, drawn from the sources:

1. Core Definition and Scope
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Standard RDF

Definition: RDF is a standard that provides a common reference model for organizations involved in the creation, update, supply, and application of referenced and structured road network data.
Purpose: It is designed to support various application areas, such as Vehicle Navigation Systems, Highway Maintenance Systems, Road Transport Informatics, and Advanced Road Transport Telematics.
Structure: It describes the structure and semantics of the core relational database schema, which includes fundamental tables like RDF_LINK, RDF_NODE, and RDF_FILE.

Unified RDF (URDF)

Definition: URDF is the relational representation of the HERE content portfolio.
Foundation: URDF uses the standard HERE RDF product as its basis (Core Data).
Key Advantage: It enables the easy creation of a single database where the RDF core data is complemented with select HERE additional content products. The relational database representation ensures semantic consistency and full referential integrity.

2. Content Integration (The Portfolio)
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The fundamental distinction lies in how supplementary data—especially complex, proprietary products—is incorporated:

| Feature | Standard RDF (Core) | Unified RDF (Integrated Portfolio) |
| --- | --- | --- |
| Core Network | Contains the core geometry (nodes, links, faces) and basic navigation attributes. | Serves as the foundation; the core data remains. |
| Additional Data | Additional content must often be managed as separate external data ("look-aside data") referenced by the core schema. | Integrates numerous additional content products seamlessly on a technical level. |
| Examples of Integrated Content | Focus is on core feature types (e.g., roads, administrative areas, core POIs). | Includes comprehensive packages like 2D/3D Landmarks, HERE Premier 3D Cities, Environmental Zones, Toll Cost, Traffic Patterns, Safety Camera, HERE Vehicle Regulations, etc. |
| Delivery Model | Delivered as a single package (no additional contents). | Enables selective downloading via individual product packages for additional contents. |

3. Technical Handling of External Files (Multimedia Attachments)
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This is the most critical technical difference, relating to how auxiliary files (like 3D models or junction view images) are linked and stored:

| Aspect | Standard RDF File Model | Unified RDF File Model |
| --- | --- | --- |
| File Referencing Tables | Uses the generic RDF_FILE and RDF_FILE_FEATURE tables. | Replaces generic tables with dedicated, unique file attachment tables for specific products, such as CDC_RDF_FILE_2D_LANDMARK and CDC_RDF_FILE_FEATURE_2D_LANDMARK. |
| File Storage (FILE_OBJECT) | The actual file content (Binary Large Object, BLOB) is not published in the standard core database; the FILE_OBJECT column in RDF_FILE is always NULL. Auxiliary data is delivered externally (as "look-aside data"). | Populates the FILE_OBJECT column. All files belonging to the additional content products are loaded for direct use. |
| Attachment Types | References file formats such as Wavefront Object (OBJ), Targa File Format (TGA), Scalable Vector Graphics (SVG), Digital Asset Exchange (DAE), etc. | These file types (OBJ, TGA, SVG) are incorporated directly via the dedicated URDF tables and delivered as BLOB/CLOB file. |

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Key take away:

If Standard RDF is a comprehensive architectural blueprint listing the core rooms and structures of a house, along with notes stating where pictures and furniture should be placed (the RDF_FILE_NAME pointing to external files), Unified RDF is the fully assembled, move-in ready house, where all the furniture, decorations, and custom technical systems (the additional content) have been physically placed and the actual digital files (the FILE_OBJECT BLOBs) are stored inside the corresponding database rooms.