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SAP BW Advanced Modelling part 1 A-DSO

  • WRITTEN BY : Shiva Aluri
  • ON : 31 Aug,2017
  • IN : BW/4 HANA
There have been many architecture level changes in SAP BW 7.5, to enable our customers to understand there is a need for complete data modelling flow with detailed screen based explanation.

Advanced DSOs:  

The introduction of Advance DSO enhancements for running SAP BW on SAP HANA as a virtual data warehouse, building upon Open ODS views and additional Composite Provider scenarios. These enhancements also included the addition of aDSOs. aDSOs help to consolidate DSOs and InfoCubes. In this section, we will walk through the various features and capabilities of aDSOs, as well as explore how these capabilities help to optimize various tasks in your SAP BW environment.

The ADSO is the only object you need for persistence. It replaces all previous types of DSOs, PSA, infoCube, Hybrid Provider.

   SAP BW ON RDBMS                                                                                                             SAP BW ON HANA   
 

                      Purpose of ADSO: only one modelling object for persistence.


This raises a question on how to deal with the specific classical modeling objects in BW:

  • The field-based structure of the PSA
  • Write Optimized DSO
  • The 3-table approach in standard DSO
  • The ‘every characteristic is key’ approach of the InfoCube.

The Advanced DSO manages to replace all of these objects by basically being all of them. In the ADSO settings you can specify the ADSO to behave like either one of these objects. SAP has provided specific templates for each use case:

  • Data Acquisition Layer
  • Corporate memory
  • Data Propagation Layer
  • Reporting Layer

Each of these templates is made up of a specific combination of settings. The data propagation layer, for example, would require ticking the checkboxes below. These settings create an object with an active table to report on, and a change log table for further data provisioning, basically creating a classical Standard DSO.

  

Inbound Table

/BIC/A1

  • Activation queue table for classic DSO.
  • Uncompressed fact table of non-SAP HANA-optimized InfoCube.

Table of Active Data

/BIC/A2

  • Same as classic DSO.
  • Compressed fact table of non-SAP HANA-optimized InfoCube.

Change Log

BIC/A3

  • Same as classic DSO. 


The Advanced DSO manages to replace all of these objects by basically being all of them. In the ADSO settings you can specify the ADSO to behave like either one of these objects. SAP has provided specific templates for each use case: 

  • Data Acquisition Layer
  • Corporate memory
  • Data Propagation Layer
  • Reporting Layer

Each of these templates is made up of a specific combination of settings. The data propagation layer, for example, would require ticking the checkboxes below. These settings create an object with an active table to report on, and a change log table for further data provisioning, basically creating a classical Standard DSO.

Benefits of ADSO:

  • Simplification of object types. The ADSO is your object for persistence with settings to fine-tune it to your specific needs.
  • Flexibility in data modeling. Because the ADSO is manageable by settings, you can start out modeling your ADSO using the Reporting Layer settings. If requirements change or you come across new insights, you can now simply change your settings to change that object into the propagation layer for example. No new object needed, this can even be done without losing data in most cases.
  • Performance of data loads and activation is optimized for HANA as ADSO is a HANA native object.

Why do you for Advance DSO?

Using HANA optimized objects, you can achieve better performance for analytical reporting and data analysis. DSOs of SAP BW are automatically optimized for activation in SAP HANA database. When you migrate SAP BW on HANA, all standard DSOs are moved to SAP HANA database in column storage.

Create an Advanced DSO Based on HANA Database

Go to SAP HANA studio → BW Modeling Tools

To create an Advanced DSO, right-click on your InfoArea and choose New DataStoreObject (advanced).
  

Provide the following details and click Finish.

  • Enter the name of DataStore
  • Description of the DataStore and   Select an Object Template.
 
Depending upon the requirement select any Model Template Ex: Standard DSO or InfoCube .
 
Click on details tab and make sure at least one infoObject as key by clicking on Manage Keys.

Next is to check and activate BW object.
 

You can also analyze the result in the Problems log of this perspective.

 

Go to BW System → Modeling → InfoProvider → Advance DSO → Right click → Create Transformation.

Create a Transformation from your Source InfoProvider(InfoCube or DSO) to Advanced DSO that you have created in HANA database.

You can observe the mapping between Source and Target.