In the ABAP RESTful Application Programming (RAP) model, a CDS Projection View is specifically designed to expose a subset of the underlying data model for a particular business scenario or application. It acts as a consumption-specific layer, selecting only the required fields, associations, and actions from the more comprehensive base (or interface) CDS view. This ensures that the OData service for a Fiori app is lean and only contains the data and functions relevant to that specific use case, improving performance and security.

A. Database view: This is a general ABAP Dictionary object for combining tables. It is not the specific RAP artifact designed for creating an app-specific data consumption layer.

B. Metadata extension: This object is used to add or override UI-specific annotations for a CDS view. It does not define or filter the data fields of the model itself.

D. Data model view: This term typically refers to the base or interface CDS view in RAP, which defines the complete, reusable data model, not the app-specific, filtered subset.

1. SAP Help Portal

ABAP RESTful Application Programming Model > Core Data Services (CDS) > CDS Projection Views: "A CDS projection view is defined on top of a CDS data model view to serve a specific business purpose. It exposes a subset of the elements of the underlying data model view and adds consumer-specific annotations."

2. SAP Help Portal

ABAP RESTful Application Programming Model > Getting Started > Steampunk Core > Develop a Fiori App > Create the CDS Data Model > Create a CDS Projection View: "You create a CDS projection view to expose the data from the underlying data model view for a specific use case. In a projection view

you can decide which elements and associations of the underlying view you want to expose."

3. SAP Help Portal

ABAP RESTful Application Programming Model > Business Object Projection: "A business object projection is a consumption-specific view on a business object. It is used to expose a subset of the business object's functionality for a particular scenario." The CDS Projection View is the data modeling artifact for this concept.