A Review of SAP HANA CDS Views

To define SAP CDS Views, let’s start with CDS. It is an acronym for Core Data Services, a robust and user-friendly programming language developed and launched by SAP. It is not necessary to go through the application server for defining and consuming models on the database with SAP CDS Views. Instead, CDS Views is a highly advanced and optimized platform to create data models with OData services that may be moved outside the applications. This is one exclusive feature of the SAP CDS Views. 

Traditional databases are based on application servers but data models on SAP CDS run on database servers. The robust in-memory database of SAP HANA can be leveraged through SAP CDS, a data modeling framework when organizations need to monitor real-time performance. 

This requirement is adequately met by optimizing operations at the level of the database and results in reduced application execution time and quick retrieval of databases. Moreover, data models presented by application servers through SAP CDS can be accessed by users through UI and SAP CDS Views. The SAP HANA Extended Application Services (SAP HANA XS) may be used to create views in SAP CDS as design-time files in the storage repository. 

The Launch and Evolution of SAP CDS Views 

SAP first introduced SAP CDS Views as a programming and virtual data model. It was offered out of the box with SAP HANA and resulted in organizations having quick and direct access to all the basic tables of the SAP HANA database. The goal of SAP at launch was to permit logic from the application server to the client-side database named ‘Code-to-Data’ or ‘Code Pushdown’. It was then extracted by the SAP CDS Views from the ABAP applications to be executed on the database. 

By introducing SAP CDS Views, SAP has radically changed the way that applications are developed and data is managed. Organizations can today carry out unlimited operations at the database level by ensuring fast and real-time performance through their in-memory database. 

While in the past the process had been to use an application server rather than a database server for database modeling, the evolution of SAP HANA has changed the basics. Now, the process entails using data modeling at the database level with the help of Core Data Services (CDS), popularly termed SAP CDS Views, to benefit from the many advantages this brings to the table.  

Types of SAP CDS Views

There are two types of SAP CDS Views. 

• HANA CDS Views: This type of CDS Views has been extensively analyzed in this post. In a nutshell, it is a programming and virtual data model that comes as a standard feature of SAP HANA. Organizations can have quick and direct access to all the tables in the SAP database.

• ABAP CDS Views: It is a critical technology for developing modern applications on SAP systems, providing improved performance in data modeling when used together with the SAP HANA database. With ABAP CDS Views, developers can create semantically rich data models and provide application services to UI clients. ABAP CDS Views, created using an enhanced version of open SQL syntax, are located in the application server (data dictionary) but process the logic in the database.

Even though data in SAP is physically stored in transparent tables, CDS Views, for data modeling purposes, is an abstraction layer on top of the tables.

Benefits of SAP CDS Views

The main benefits of SAP CDS Views are as follows. 

• Since SAP CDS Views is a code-to-data technology in ABAP, all computing and calculations are done directly on the database layer instead of the application server.

• SAP CDS Views features are available outside the SAP native applications as they are less conventional in SE11 views.

• CDS View on SAP can be operated on any database platform supported by SAP as it works independently of the database  

• Because ODATA service annotations are published directly from SAP CDS Views, CDS automatically supports all client operations  
• SAP CDS Views support all Aggregation and Numeric functions as well as automatic client handling 

• CDS Views provides support to inner join, cross join, full join, outer join, and right outer join          

These are among the most important benefits of SAP CDS Views. 

The Functions of SAP CDS Views

One of the most important requirements of today’s big data-based businesses is to carry out real-time data reporting and analytics on transactional data. This has been ensured by the power of HANA as large queries (analytics) on S/4 HANA can be optimally performed without needing a separate data warehouse or facing any lack or degradation in performance. SAP CDS Views can directly create VDMs (Virtual Data Models) in ERP that can be used as high-performing front-end tools. 

Users can now define a view in an SAP CDS Views document with SAP HANA XS (SAP HANA Extended Application Services) that can be stored as design-time files in the repository and read by applications developed specifically for this purpose. These files located in the data repository have definitions and can be moved to other SAP HANA systems like a delivery unit. 

SAP CDS Views may be used for real-time data analytics on live transactional data even without determining the underlying tables/structures. This is because of the advanced features of the in-built SAP S/4 HANA Embedded Analytics. These views are combined with both modified new views or used directly to create new views.  

After activation of a CDS document, a catalog object for each object as given in the document is correspondingly generated.  The specific type of object that is generated determines the exact location of the catalog. For example, for SAP CDS Views definition, the catalog object corresponding to SAP HANA XS classic is generated in the location <SID> Catalog <MYSCHEMA> Views.