Core Data Services and CDS Views
New paradigm requires new infrastructure
With the introduction of S/4HANA and the SAP HANA platform, a paradigm shift in the development of SAP applications is taking place: all data-intensive work is being shifted to the database in order to achieve the best possible performance.
When modeling with CDS, the data models are defined on the database and not on the application server. CDS views are converted as database views, so that all data accesses, calculations are performed at database level.
Core Data Services extend SQL and use their own Data Definition Language (DDL). They can be provided with additional annotations or associations. Using DDL enables CDS views to define database tables, database views and data types.
In the time before SAP HANA, the SAP stack used the architecture of the application server with the tools ABAP Dictionary and Data Modeler to create the data model.
With CDS Views, you can differentiate between ABAP CDS Views and HANA CDS Views depending on the version / SAP stack. In principle the CDS views under ABAP and HANA follow a uniform concept with identical purpose for data modelling, but due to the possible use of non-HANA databases in a SAP ECC system, ABAP CDS views use OpenSQL, whereas HANA CDS views use native SQL.