Powering Streamlined Data Access in SAP
Welcome back to our exploration of the Virtual Data Model (VDM) in SAP S/4HANA! In part one, we unraveled the essence and fundamentals of VDMs. Now, let’s delve deeper into the VDM architecture and its practical implementation.
A VDM’s Building Blocks
VDM architectures are built upon a layered architecture, offering a structured and efficient way to access data. Here’s a breakdown of these fundamental layers:
- Consumption Layer: This is the user interface where consumers interact with the data. It could be a business application like SAP Fiori, an analytical tool, or a custom application.
- Reuse Layer: This layer acts as a bridge, allowing different consumers to access the same data definition without redundancy. It houses reusable CDS views built on top of the data source layer.
- CDS (Core Data Services) Layer: This layer sits at the core of the VDM, interacting directly with the data source (e.g., SAP HANA database tables). It primarily consists of:
- CDS Entities: These represent real-world objects and their attributes, mapped to underlying database tables or views.
- CDS Views: These are virtual data models defined using CDS annotations, combining data from various entities and providing a simplified data view for the reuse layer.
Data Flow Through the VDM Layers:
Imagine a user accessing customer data through a SAP Fiori application (consumption layer). The request would flow through the VDM layers as follows:
- Consumption Layer: The user interacts with the application, triggering a data request.
- Reuse Layer: The application retrieves the relevant CDS view from the reuse layer.
- CDS Layer: The CDS view in the reuse layer interacts with the underlying CDS entities, fetching data from the data source (e.g., HANA tables).
- Data Source: The requested data is retrieved from the underlying data source and sent back to the application.
- Consumption Layer: The application receives the data and presents it to the user.
This layered structure promotes efficiency by enabling reuse of the same data definition across different applications and simplifies data access for both developers and end users.
Building and Deploying Your VDM: A Practical Guide
Creating a VDM involves defining CDS entities, views, and annotations using the SAP HANA development tools. Annotations provide crucial metadata that guides the system on how to interpret and utilize the data model.
Here’s a simplified overview of the process:
- Identify Data Source: Determine the underlying data source (e.g., HANA tables) for your VDM.
- Define CDS Entities: Model real-world objects and their attributes using CDS entities, mapping them to the data source.
- Create CDS Views: Build CDS views using annotations to define the desired data structure and combine data from different entities as needed.
- Deploy the VDM: Activate the CDS entities and views for them to be recognized by the system.
VDM Deployment and Consumption Options:
Once your VDM is built and deployed, you can expose it to users through various channels:
- SAP Fiori: Leverage pre-built Fiori applications or develop custom applications to access and display data from the VDM.
- OData Services: Expose the VDM as OData services for consumption by external applications or custom development.
Embrace the Power of VDM Architecture:
By understanding the layered architecture and implementing VDMs effectively, you can unlock several benefits:
- Simplified Data Access: Provide users with a consistent and user-friendly way to access data from various sources.
- Improved Data Quality: Enforce data consistency and integrity through centralized data definitions.
- Enhanced Reusability: Share and reuse data definitions across different applications, reducing development time and effort.
- Flexibility: Adapt the VDM to evolving business needs by adding new entities, views, and annotations.
VDMs offer a powerful and efficient approach to data management in the SAP S/4HANA landscape. By delving into its architecture and implementation, you can harness its potential to streamline data access and empower informed decision-making across your organization.