What is the effect of attaching a system field to an input parameter of a CDS view entity?

Attaching a system field, such as sy-langu, to an input parameter of a CDS (Core Data Services) view entity allows the CDS view to automatically utilize the value of that system field as its default. This functionality is particularly useful for ensuring that the CDS view can adapt to certain system settings, such as the user's language preferences.

By selecting the correct answer, the statement accurately points out that even when a system field is attached, users still have the flexibility to override the default value set by that system field with their own specific value. This means that if a developer or end user wants to input a different value for that parameter when querying the CDS view, they can do so without restrictions. This flexibility is essential for providing dynamic functionality within ABAP applications where the context might change based on user selections or program logic.

The interaction of user-defined values with system fields represents a powerful feature of CDS views, emphasizing their adaptability and the seamless integration of system parameters with user input. This characteristic makes the correct answer an important principle to understand when working with CDS views in SAP development.