Tuesday, March 22, 2022

Flavors of aDSO object

aDSO objects came in BW with many flavors. Mostly the different flavors corresponds to different layers of Enterprise Data Warehouse Architecture (like LSA++ for SAP BW/4HANA or LSA++ for classic BW) categories:


1 Data acquisition layer - including corporate memory

2.1 Corporate memory - compression capabilities

2.2 Corporate memory - reporting capabilities

3.1 Data warehouse layer - delta calculation

3.2 Data warehouse layer - data mart


Or to different InfoProvider objects as we know them from classic BW:

4 Standard DataStore object

5 Write-optimized DataStore object

6 InfoCube


Or from planning point of view:

          7 Planning in InfoCube-like manner

          8 Planning on direct update

 

BW modeling tools offers a template to make a decision of what type of the aDSO objects would a developer pick via called Templates for Modeling the Data Warehousing Layers. The template appears in SAP HANA Studio (BW Modeling perspective). Developer can pick from the template and the new aDSO object’s settings are setup by the system.


Here is a brief description on how the particular predefined property settings for the aDSO object look like for different aDSO object type:

 

1 Data acquisition layer - including corporate memory: No properties are selected, object corresponds to PSA layer as known in the classic BW.

 

2 Corporate memory

2.1 compression capabilities: "Active data" check box is enabled. Data is loaded into the inbound table. Data can be compressed (activated). However, the request cannot be deleted anymore after the activation. No request based deletion of the request possible after the activation. While querying such the aDSO the active table is accessed.

2.2 reporting capabilities: "Active data" and "Keep Inbound data extract from Inbound Table" check boxes is enabled. Data is stored redundantly in the inbound and in active table as well. This enables activation of the data and deleting the activated data requests. Data can be reloaded from inbound table as well (detailed information is not lost). While querying such the aDSO the active table is accessed.

 

3 Data warehouse layer

3. 1 Delta calculation: "Active data" and "Write Change Log" check boxes is enabled. Data is loaded to inbound table. Another checkbox called "Unique Data Records" can be enabled too in case only unique data is loaded to the aDSO. While querying such the aDSO the active table is accessed thus data need to be activated prior the querying. Change log table is used to enable deletion of activated requests thus the aDSO can be reloaded again. Behavior of this type of the aDSO is similar to standard DSO (classic) like object. Mechanics here is called unstable navigation as while querying only active table is used.

 

3.2 Data mart: "Activate Data" and "All Characteristics are Key, Reporting on Union of Inbound and Active Table" check boxes is enabled. Behavior of this type of the aDSO is similar to standard InfoCube object (cube-like object). Its inbound table is similar to F (not compressed data) table of the cube and active table is similar to E (compressed data) table of the standard cube. This type of the aDSO object supports so called stable navigation as while querying both the tables are used (via union): inbound and active too.

 

4 Standard DataStore object: so called classic DSO-like aDSO object - See point 3.1.

 

5 Write-optimized DataStore object: No properties are selected.

 

6 InfoCube:  so called cube-like aDSO object - See point 3.2.

 

7 Planning in InfoCube-like manner: "Active Data", "All Characteristics are Key, Reporting on Union of Inbound and Active Table" and "Planning Mode" check boxes is enabled.

 

8 Planning on direct update: "Direct Update" and "Planning Mode" check boxes is enabled.

 

Notice that the templates for the Modeling the Data Warehousing Layers are only available for classic BW systems and not in BW4/HANA.

 

More information:

Templates for Modeling the Data Warehousing Layers

No comments: