SAP Core Data Services: Stop Writing SQL — Start Architecting Virtual Data Models

When customers talk about Core Data Services (CDS) in SAP S/4HANA, the conversation often stops at SQL. And that’s understandable — CDS is built on SQL, so the first instinct is to treat it like a new way of writing queries.

But here’s the truth: if you stop at SQL, you’re doing it wrong.

SQL Queries vs. Virtual Data Models (VDM)

• SQL in CDS: Fine for basic data extraction. You can quickly build a CDS view that pulls line-item data for reporting.
• VDM in CDS: A different level entirely. Virtual Data Models replicate the enterprise data modelling foundation of SAP BW — but virtually, inside S/4HANA.

VDM is where the real value lies for reporting and analytics. It’s not just about pulling data; it’s about structuring it for business meaning, scalability, and performance.

What VDM Enables

• Define dimensions and measures
• Build cubes with fact and dimension views
• Leverage and enhance standard SAP content views
• Apply different aggregation types depending on reporting needs
• Configure exception aggregation for advanced analytics

This is the difference between a developer writing a query and a data modeller architecting a reporting foundation.

Why Clean Core Matters

A well-versed CDS developer doesn’t just build views — they build them in a way that preserves the clean core principle. SAP’s own guidance emphasizes that CDS views are the key to a clean core because they allow you to extend and adapt delivered content without modifying the underlying system.

Here’s what that looks like in practice:
• Extension Views: Add custom fields or calculations by extending standard CDS views, rather than rewriting them.
• Annotations: Use SAP-provided annotations to define cubes, measures, and exception aggregations in line with SAP’s analytical framework.
• Namespace Discipline: Keep custom CDS views separate and documented, ensuring they’re reusable and upgrade-safe.
• Enhance, Don’t Replace: Build on SAP-delivered CDS content instead of duplicating it, which keeps the system agile and resilient during upgrades.

This layered approach ensures that CDS enhancements remain scalable, reusable, and upgrade-resilient — the essence of clean core.

Why It Matters for Customers

If your only goal is raw data extraction, a SQL-style CDS view may be enough. But if you want embedded analytics, real-time reporting, and scalable insights, you need consultants who understand VDM and clean core methodology.

At CONTAX, we’ve spent decades building enterprise data models in SAP. Our consultants know how to design CDS views that leverage VDM, optimize for performance, and expose data cleanly to tools like SAP Analytics Cloud, Power BI, Tableau, and Qlik — all while keeping the system clean and future-ready.

Red Flags to Watch For

• Can’t explain dimensions, cubes, or exception aggregation
• Only build “flat” SQL-style CDS views
• Don’t mention clean core methodology

…that’s a sign they may not be delivering the full value of S/4HANA analytics.

Our Commitment

At CONTAX, we ensure our data and analytics consultants have a solid background in enterprise data modelling and virtual data modelling in S/4HANA. We tailor our approach to each business requirement, ensuring that CDS is not just a query tool — but a foundation for analytics excellence, built the right way.

If you’d like to learn more, reach us at www.contax.com or info@contax.com.