Core Data Services (CDS) is a key feature in the context of ABAP on SAP HANA, providing a declarative and semantically rich way to define and consume data models. CDS plays a crucial role in defining data structures, views, and associations in ABAP development on the SAP HANA platform. Here are key aspects of CDS in the context of ABAP on HANA:

1. Declarative Data Modeling:

   • CDS allows developers to define data models in a declarative manner, specifying what data structures should look like rather than how to retrieve them. This approach simplifies data modeling and reduces the need for low-level SQL coding.

2. Structured Data Definitions:

   • With CDS, developers can define structured data definitions such as tables, views, and associations using a syntax that is both expressive and concise. This includes the definition of entities, elements, and annotations.

3. Reuse and Composition:

   • CDS supports the reuse of existing data definitions, allowing developers to compose complex data models by combining reusable elements. This promotes a modular and maintainable approach to data modeling.

4. Exposure of Database Views:

   • CDS views can be used to expose database views, which are implemented on the SAP HANA database. These views can be consumed by applications for efficient data access.

5. Integration with ABAP Dictionary:

   • CDS seamlessly integrates with the ABAP Dictionary, providing a unified approach to managing data definitions. CDS views are registered in the ABAP Dictionary, and developers can leverage the existing tools for data modeling.

6. Annotation-Based Development:

   • Annotations in CDS allow developers to add metadata and semantics to data models. This metadata provides additional information about the nature of the data and is used for various purposes, including UI annotations and data analysis.

7. Usage in Data Retrieval:

   • CDS views are used in data retrieval scenarios, providing a higher level of abstraction over database tables. They can include joins, aggregations, and filters, simplifying the process of fetching and manipulating data.

8. Consumption in ABAP Programs:

   • CDS views can be consumed directly in ABAP programs. Developers can use CDS entities in Open SQL statements, making it straightforward to work with CDS-defined data models.

9. Integration with Fiori Elements:

   • CDS views are commonly used in conjunction with SAP Fiori applications. Fiori Elements, which are UI building blocks for Fiori applications, can consume CDS views, making it easier to build responsive and adaptive user interfaces.

10. SAP HANA Native Features:

    • CDS leverages native features of the SAP HANA database, such as database-level aggregations, projections, and optimizations. This leads to improved performance in data retrieval operations.

11. Support for Associations:

    • CDS supports the definition of associations between entities, allowing developers to model relationships between different data structures. This is particularly useful in scenarios where data needs to be linked across tables or views.

In summary, CDS in the context of ABAP on HANA provides a modern and expressive way to define data models, enabling developers to work more efficiently and take advantage of the features provided by the SAP HANA database. It promotes a unified approach to data modeling and consumption within the ABAP development environment.