CDS Views are implemented in S4 system. We created two custom CDS one for sales and other for billing flow. Once the CDS view is ready it is then exposed to B4 through RFC Connection. Data Sources are created in B4 system to get CDS data. Transformation / DTP are created to push data from Data sources to ADSO.
Calculation Views and Composite provider helps us implement Mixed modelling in BW4HANA where a model from Native HANA (Calculation views) is exposed to BW object (Composite provider).
Calculation views aids in implementing logic directly on data base layer, thereby reducing execution time by eliminating the need to push the data to application layer. It helps calculate data on the fly to cut down unload and reload phases to zero when it comes to business-related changes in data staging or extension/reduction in a data model. Unlike Classical BW systems there is no need to clear delta queues whenever there is a change in logic which facilitates zero downtimes during go live.
Composite Provider helps us combines data from several analytic indexes (Calculation Views in our Scenario) or from other Info Providers (by Join or Union – Info objects in our Scenario) and makes this data available for reporting and analysis. UNION and JOIN operations are executed in HANA and not on application server. CP also help us implement complex logic such as Key and Text display for field, Attributes of Info object.