Top 20 ABAP CDS Interview Questions and Answers

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Dear SAPLearners, in this blog post we will discuss about ABAP CDS interview questions, which are most commonly asked interviews.

ABAP CDS Interview Questions with Answers

1. What is ABAP Core Data Services (CDS)?

ABAP Core Data Services is the implementation of the general CDS concept for AS ABAP. It enables developers to define semantic data models on the standard database of an AS ABAP and supports ABAP RAP using behavior models. It provides enhanced access functions compared to traditional DDIC database tables and views.

2. What are the main benefits of using ABAP CDS?

The main benefits of ABAP CDS are:

  • Enables optimization of ABAP SQL-based applications
  • Particularly effective with SAP HANA database, utilizing its in-memory capabilities
  • Supports semantic data modeling
  • Provides enhanced access functions
  • Enables ABAP RAP (RESTful Application Programming) support
  • Allows data exchange between different platforms using CSN

3. What are CDS Annotations and what is their purpose?

CDS Annotations are metadata additions to CDS objects. They can be specified in DDL, SDL, and DCL source code and can be outsourced to metadata extensions. They serve to enhance CDS objects with additional metadata information and can be defined using annotation definitions that prescribe how an annotation should be used.

4. What are the different types of CDS Data Definitions?

Following are different types of CDS data definitions

  • CDS View Entities
  • CDS Projection Views
  • CDS Table Functions
  • CDS Hierarchies
  • CDS Custom Entities
  • CDS Abstract Entities

5. What is CSN (CDS Schema Notation) and why is it important?

CSN is a data format used for data exchange between data models. It enables data exchange between ABAP CDS and other platforms, such as SAP Analytics Cloud (SAC). It’s important because it facilitates interoperability between different SAP platforms and solutions.

6. What are CDS Type Definitions and what are their types?

CDS Type Definitions are created using CDS TDL and define data types natively in ABAP CDS. There are two main types:

  1. CDS Simple Types – defines elementary data types
  2. CDS Enumerated Types – defines enumerated types

7. What is CDS Access Control and how does it work?

CDS Access Control is based on CDS roles defined in CDS DCL (Data Control Language) in DCL source code. When CDS SQL entities with assigned CDS roles are accessed, additional access conditions are automatically evaluated, providing a security layer for data access.

8. What is the difference between CDS View Entities and CDS Projection Views?

CDS View Entities use SQL to access other data sources and can be enriched semantically using annotations. CDS Projection Views, on the other hand, are based on an existing CDS view and project only a subset of its elements, allowing for more focused data access.

9. What are CDS Table Functions?

CDS Table Functions are CDS entities that are implemented in AMDP (ABAP Managed Database Procedures) functions and return a tabular result set. They allow for complex data operations that return multiple rows of data.

10. How are CDS objects transported between systems?

CDS objects are transported using the CDS source code. When transported to the target system, the actual objects (like CDS entities) are created through activation in that system.

11. What development tools can be used to program CDS source code?

CDS source code can only be programmed in the Eclipse-based ABAP development tools for Eclipse (ADT). There are specific editors for:

  • Data Definition Language (DDL)
  • Service Definition Language (SDL)
  • Data Control Language (DCL)

12. What are CDS Custom Entities?

CDS Custom Entities are special CDS entities designed for data models whose runtime is implemented manually. They provide flexibility in implementing custom data access and processing logic.

13. What is the purpose of CDS Abstract Entities?

CDS Abstract Entities describe only type properties and don’t instantiate database objects. They’re useful for defining reusable structures and types that can be referenced by other CDS entities.

14. What are CDS Function Definitions and their types?

CDS Function Definitions are created using CDS FDL and allow definition of user-defined CDS functions that encapsulate reusable algorithms. Currently, the main type is CDS Scalar Functions, which are implemented in AMDP functions and return scalar results.

15. How do CDS Hierarchies work?

CDS Hierarchies are CDS entities that create an SQL hierarchy from a data source. They allow for the representation and processing of hierarchical data structures within the CDS framework.

16. What are CDS tuning objects?

CDS tuning objects are ABAP tuning objects for CDS objects that define technical settings and tunings. They can be transported separately from the main CDS objects, allowing for system-specific optimizations.

17. What are CDS System Entities?

CDS System Entities are predefined CDS entities available for common usage in ABAP CDS and ABAP SQL. They provide standard functionality that can be reused across different implementations.

18. Why were DDIC-based views replaced by CDS view entities?

DDIC-based views became obsolete from release 7.55 onwards because CDS view entities provide enhanced functionality and are no longer based on dictionary objects, offering better performance and more features.

19. What is the role of CDS in ABAP RAP?

ABAP RAP (RESTful Application Programming) is based on both the data models defined in ABAP CDS and special RAP objects that model behavior. CDS provides the foundation for data modeling in RAP applications.

20. How can CDS source code be viewed in systems without Eclipse?

While development requires Eclipse-based tools, CDS source code can be displayed in the Repository Browser of the ABAP Workbench, allowing for code review in traditional SAP GUI environments.

21. What are “Supported Capabilities” in CDS views, and how do they help developers?

It is possible for a single CDS view to provide many capabilities such as a data source, association target, or analytical provider. Supported Capabilities indicates clear use cases for CDS views and provides an idea of the most efficient ways to use a CDS view.

The supported capabilities of a CDS view are defined using annotation and can be attached to any given CDS view. Each CDS view can have multiple supported capabilities. 

Conclusion

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