Core Data Services in ABAP

Core Data Services (CDS) in ABAP allow defining semantically rich data model in DDL resource object. They are integrated into the ABAP infrastructure and allow to push more calculations into the database.

The CDS consists of the following three sub-languages addressing the different sub-domains of data modelling:

• Data Definition Language (DDL): DDL part of CDS allows you to define semantically rich database tables and views (CDS entities) and user-defined type in database.
• Query Language  (QL): Views defined using the CDS DDL can be consumed in ABAP program by using Open SQL in ABAP.
• Data Control Language (DCL): DCL is used to define authorizations for CDS entities. 

CDS are not only an integral part of SAP HANA, but also are integrated into the ABAP dictionary and language. This new repository object types DDL and DCL for defining enhanced view entities in ABAP allow you to push more intensive data calculations into the database than is possible using the classic ABAP dictionary views.

You can use CDS views to read data and calculate data while reading the data. The CDS view does not support the data modification as of now.

To create the CDS view, do the following:

• Use the Abap Development Tools. The ABAP workbench does not support the new type of ABAP repository objects called DLL Sources.
• In the ABAP Project Tree, select the package to contain the CDS view and right click to choose menu entry New --> Other ABAP Repository Object --> Dictionary --> DDL Source.
• Use the DDL Statement DEFINE VIEW and SQL-like syntax to define the view.