Ecc Vs Soh Vs S4h

SAP ABAP CDS Views Vs. SAP HANA CDS Views – What Are the Differences? Table of Contents    

SAP CDS Views SAP ABAP CDS Views SAP HANA CDS Views Compatibility between SAP ABAP CDS Views and SAP HANA CDS Views

SAP ABAP CDS views and SAP HANA CDS views are not the same. But they are similar. They are two different shapings of one concept. Both are based on the same specifications. But the aims between the views are different. SAP CDS Views SAP CDS views are part of SAP’s new programming model. The core idea of the programming model is to push the logic from the application server to the clientside and the database. And CDS views are part of pushing the logic to the database and the client-side as well. Pushing the logic to the database because they take most of the logic from an ABAP application and execute it on the database instead of on the application server.

SAP’s new programming model – code to data.

And they are pushing the logic to the client-side because CDS Views are able to control SAP UI5 Smart Controls and SAP Fiori Elements by annotations through OData services that can be generated from a CDS view. Therefore, the logic goes to the client-side because of the logic of the SAP UI5 controls delegated by CDS views. CDS views are from the concept similar to ABAP dictionary views. They provide pre-defined SQL queries to one or more database tables. That allows effectively and comfortably to connect and access data. But a SAP ABAP CDS view can do a lot more than a SAP ABAP dictionary view. An ABAP dictionary view is actually just an ABAP structure. An ABAP CDS view generates an ABAP structure too but also more on top of that. Overall, an ABAP CDS view generates or can generate:    

ABAP structure database structure Open SQL structure OData service

However, this is what ABAP CDS views and HANA CDS views have in common. Now to the differences between ABAP CDS views and HANA CDS views. SAP ABAP CDS Views SAP ABAP CDS views are defined at the level of the ABAP application server. The views are created and maintained in DDL files which reside in the ABAP application server. They are part of the Data Dictionary (SE11) and therefore, part of the ABAP transport system, life cycle management, etc. The views using Open SQL. ABAP CDS views aim to support the development of ABAP applications. Whereby, the type of the database system irrelevant is. It does not have to be HANA. Therefore, the main focus of ABAP CDS views is to create views and not models.     

reside application server work with any database Open SQL ABAP applications main focus to create views

SAP ABAP CDS views reside in the application server in the Data Dictionary but processing the logic in the database. SAP HANA CDS Views SAP HANA CDS views are defined at the level of the HANA database. The views are created and maintained in DDL files (Data Definition Language files) which reside at the database level in the HANA XS (HANA Extended Application Services). The views using Native SQL. HANA CDS views aim to support the development of native applications of SAP HANA. They are using features that are specific for SAP HANA. Therefore, they can only be used with a HANA database. The main focus of HANA CDS Views is to create models.     

reside HANA database (HANA XS) work only with HANA database Native SQL native HANA applications main focus to create models

Compatibility between SAP ABAP CDS Views and SAP HANA CDS Views SAP ABAP CDS views and SAP HANA CDS views are two different CDS implementations. Their technical compatibility is not guaranteed. Because 

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They run on different platforms: ABAP CDS views reside in the ABAP application server (ECC, S/4). HANA CDS views reside in the HANA database (HANA XS). They have different requirements: ABAP CDS views support the implementation of ABAP applications. HANA CDS views support the development of native HANA applications.

Therefore, ABAP CDS views and HANA CDS views have different functionalities and release cycles.

SAP ABAP Dictionary Views Vs. SAP ABAP CDS Views – What Are the Differences? Table of Contents     

ABAP Dictionary Views ABAP CDS Views ABAP Dictionary Views Vs. ABAP CDS Views 5 Reasons to Use ABAP CDS Views Instead of ABAP Dictionary Views in an ECC System Performance Difference Between ABAP Dictionary Views and ABAP CDS Views

ABAP dictionary views or Database Views are created in the SE11 in the ABAP dictionary. ABAP CDS views are created in Eclipse – for now. The guess is that sooner or later they can be developed in the Web IDE as well. Where an ABAP dictionary view and an ABAP CDS views get created is the first obvious difference. But first things first – what are ABAP dictionary views and what are ABAP CDS views. ABAP Dictionary Views ABAP dictionary views fetch from the database pre-defined data. The ABAP dictionary views get from the database by SQL Statements the data needed for an application to process the desired result. For example, an ABAP application wants to output all products. For this, the application needs to fetch from the database the necessary data of a product. And instead of doing this directly by an SQL statement, the application uses an ABAP dictionary view. The ABAP dictionary view gets the data of a product from the tables of the database by SQL. It connects all for a product necessary tables of the database by Inner Joins and selects from the tables all the necessary fields for a product. Then the ABAP application does not use an SQL statement directly to get the data of the product from the database but the ABAP dictionary view. The ABAP

dictionary view is like an additional layer between the ABAP application and the database. For example, the name of the ABAP dictionary view is ZPRODUCTS. It contains all tables and fields which are necessary for a product. In the ABAP code the ABAP dictionary view could be used like this: 1

SELECT * FROM zproducts

2

ORDER BY product_name

3

INTO TABLE @DATA(result).

4 5

cl_products_output=>display( result ).

An ABAP dictionary view is a view for one or more database tables. It is literally a view. Imagine you are looking through binoculars at a database. You only focus on certain tables or even just one table. Same goes with ABAP dictionary views: You pick one certain table or bundle certain tables together. Plus, you can also focus only on certain fields from those chosen tables. For example, a database contains a bunch of tables. Your application aims to return data which resides in three of the tables of the database. And only one field of each table is necessary. Here comes the view: The view connects those three tables and picks only the fields of the tables which are needed. When you activate an ABAP dictionary view, then a SQL view is created. This SQL view contains the SQL syntax of the defined ABAP dictionary view. For example, if you connect more than one table with an ABAP dictionary view, then the SQL statement of the SQL View does this by an Inner Join. ABAP CDS Views ABAP CDS views were introduced in ABAP 7.40 SP05. There are two variants: ABAP CDS views and HANA CDS views. They are both parts of the new programming model of SAP. The new programming model of SAP pushes the code and therefore, the logic from the application level down to the database level and up to the front-end or

client-side. CDS views pushing the logic down to the database and up to the client-side. Because they take logic from an ABAP application from the application server and execute it instead at the database level, plus, CDS views allow the control of SAP UI5 Smart Controls and Fiori Elements through annotations and OData services which delegate logic to those controls and therefore the client-side. Before the new programming model of SAP, the concept was to fetch with predefined SQL statements a data package from the database and to process it at the application level to the required result. ABAP dictionary views commonly described the pre-defined SQL statements. The new programming model does transfer the processing of the SQL fetched data from the application level down to the database level. And it does so by CDS views. The CDS view does not only pre-define the SQL statement but also contain the logic to process the by the SQL statement fetched data. The aim is to do as much logic as possible at the database level by CDS views. In the case of ABAP CDS views, the views reside still in the application level in the Data Dictionary (SE11). But a CDS view can transfer more logic in compare to an ABAP dictionary view from the application server to the database through SQL. Nevertheless, an ABAP CDS view still pushes the result of the SQL statement back to the application server. In the old programming model was the principle the less database load, the better. In the new programming model is the principle the more database load, the better. It is about Code-to-Data and not anymore Data-to-Code – Code-to-the-Database and not anymore Datafrom-the-Database-to-the-Code. ABAP Dictionary Views Vs. ABAP CDS Views First, ABAP dictionary views in compare to ABAP CDS views is not to be confused with ABAP CDS views in comparison to HANA CDS views. ABAP Dictionary Views  

reside in the application server support all kinds of databases

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limited basic SQL functions as INNER JOIN or SELECT

ABAP CDS Views     

reside in the application server support all kinds of databases basic SQL functions as INNER JOIN, OUTER JOIN, UNION or SELECT calculations, aggregations, grouping nested views

HANA CDS Views

reside integrated into the database (HANA XS)  support only HANA databases  all the other features of ABAP CDS Views  explicit features for the HANA database 5 Reasons to Use ABAP CDS Views Instead of ABAP Dictionary Views in an ECC System 

There are 5 reasons to use ABAP CDS views instead of ABAP dictionary views in an ECC system: 1. upward compatibility to S/4 2. easy generation of full-fledged OData Services 3. easy use of SAP UI5 Smart Controls and Fiori Elements 4. implicit authorization checks 5. performance boost (see below) Performance Difference Between ABAP Dictionary Views and ABAP CDS Views Between an ABAP dictionary views in an ABAP stack with a version of at least 7.40 SP05 and CDS views is no performance difference. Such an ABAP stack with or without an ABAP dictionary view and an ABAP CDS view use exactly the same SQL behind the scenes. That means the performance is the same if you execute the same SQL statement with or without an ABAP dictionary view in an ABAP Stack or through an ABAP CDS view. But there is a performance difference in so far that ABAP CDS Views are more flexible. One can make more complex selections by ABAP CDS Views and therefore can omit post-processing of data. For example, with the use of an SQL UNION in an ABAP CDS view.

Best Practices for SAP CDS Views Use the Virtual Data Model for CDS Views Use Type Annotations for Basic Views, Composite Views, and Consumption Views Use the respective type annotation for basic, composite, and consumption views in the DDL file:

@VDM.viewType: #BASIC @VDM.viewType: #COMPOSITE @VDM.viewType: #CONSUMPTION

  

1

@VDM.viewType: #BASIC

2

define view I_BusinessPartner ... {

3

key BusinessPartner,

4

...

5

}

SAP uses the annotation @VDM.viewType for internal structuring and interpretation of the CDS views. For example, in the Fiori View Browser in S/4 HANA systems. Use Naming Conventions for Basic Views, Composite Views, Consumption Views, Remote API Views, and Value Helper Views The SQL View Name can have maximal 16 characters, and the CDS View name can have maximal 30 characters. Use Z, Y, or the registered namespace of the company as the first character in every name to signal that it is a custom file and not a SAP file. And when referring to SAP business entities reuse the field names defined by SAP. When creating own field names or when extending SAP delivered views then use as a prefix a YY or ZZ. SQL View Name

– for example, ZIBPADDR. The consists of

1. Y, Z or the registered namespace of the company, 2. I (interface view – basic & composite views), C (consumption view), or A (remote API view) The is 1. all written together, 2. all in upper case letters, 3. if the view is a value helper cds view a VH at the end, for example, ZCBPADDRVH. A value helper cds view is always a consumption view. CDS View Name

– for example, ZI_BPNameAddress. The consists of 1. Y, Z or the registered namespace of the company, 2. I (interface views – basic & composite views), C (consumption views), or A (remote API views), 3. an underscore _. The is 1. all written together, 2. in CamelCase, 3. if the view is a value helper cds view a VH at the end, for example, ZC_BPNameVH. A value helper cds view is always a consumption view.