Core Data Service Views (CDS Views)
The traditional data model for ERP systems is complex, and a complex data model causes the application code to be complex. Up to 70% of application code is built specifically to enhance the performance of an application and adds no value to the core business function. A complex data model and complex code lead to high efforts in integration with other applications and enhancements impeding agility.
SAP HANA, the database on which SAP S/4HANA is built, can generate any view of the data at run-time, all from the same source tables – doing away with the need for aggregates and indexes. This simplification shrinks the application code needed, resulting in an agile core data model and simplified application code.
The following figure explains the data model:
The data lake is at the lowest level where data is stored in database tables.
Virtual Data Model views are a layer on top that make data from the database tables easier to understand.
There are two overarching view types, Interface views and Consumption Views:
Interface Views are the most important component in the virtual data model. They have models of reusable entity views, which focus on business scenarios.
Interface Views consist of basic views and composite views
Basic Views access database tables directly and help interpret the database table fields,
Composite Views project, calculate, join, filter, and aggregate data from basic views and other composite views. These can be used, for example, as analytical cube views.
Consumption Views form the top layer of the virtual data model and are designed for a particular purpose with specific requirements, such as to be used by a particular transactional or analytical app such as G/L journal entries or cost center reporting.
There are two types of consumption views:- Consumption CDS Views allow you to create simple KPI or report tiles using the Manage KPI and Manage Reports apps.
Analytical Queries use the Analytical Engine and allow for complex calculations at runtime.
As a business user you will access data in the user interface only.
A report is consumed by end-users and is a simple chart or table based on multiple measures and dimensions.
Custom Analytical Queries transform and organize raw data delivered from business documents into a meaningful grid providing the fields required to design a query. You select the required fields and set filters in your query without having to know the query language or the technical details.
Semantic tags are short text identifiers that you configure and use to represent key figures. You assign semantic tags to the nodes of the financial statement version. This keeps report definitions stable even as the chart of account expands, and new financial statements are created.
Key Performance Indicators can be utilized in the Manage KPI and Reports apps allowing you to create applications that can be launched directly from SAP Fiori Launchpad. You can configure metrics in the KPI, visualize the data either in chart or table format, and analyze the data of different business units belonging to an organization.