“We study the past to understand the present.” – William Lund
More and more customers approach us to learn more about BW 7.5 and BW4/HANA. All the more reason for us to start a new blog series to take a closer look at this subject. Let us start by examining the history of SAP BW and then move on to outlining the subject areas we will be covering over the coming weeks.
For this article, the past refers to the SAP BW modelling and the present to SAP BW/4HANA modelling.
Most organizations and individual users are still not sure which are the differences between SAP BW(old modelling) and SAP BW/4HANA.The purpose of this article is to put things into perspective and to provide you a clear answer regarding this topic.
SAP BW History – a short overview
What are the differences between SAP BW and SAP BW/4 HANA?
One of SAP’s main goals is to simplify the system. Consequently, it bundles together objects and processes and reduces the number of steps involved.
1. Modelling Objects
A quick comparison between the modelling objects accessible in the classic SAP BW application and those in SAP BW/4HANA may help illustrate the level of modelling simplification accomplished.
In the upcoming articles in our series we will introduce you to the new Providers, starting with ADSOs.
2. Data Flows
The central entry point for modelling in SAP BW∕4HANA is the data flow. This defines which objects and processes are needed to transfer data from a source to SAP BW∕4HANA and cleanse, consolidate and integrate the data so that it can be made available for analysis and reporting. SAP BW∕4HANA is using a new integrated layer architecture (Layered Scalable Architecture – LSA++).
The classic SAP BW is using LSA, the old version of LSA++. This layer is more restrictive and not so flexible with the data.
One of the major benefits of using LSA++ is the reduction in the number of persistence layers. This has two effects:
For one, it improves data processing performance: You spend far less time saving and activating!
Second, this reduces the data volume. Given that storage place was not considered a critical factor, it used to be that redundancies were deliberately used in the BW system to improve read performance. But with the advent of HANA, things changed profoundly. Main memory is expensive, both in terms of hardware when compared to hard disk storage, and in licensing terms, as HANA is licensed as main memory. Another benefit is that the reduction in “physical” layers allows for far more flexibility in system design.
3. Source Systems
SAP is also pursuing its simplification approach when it comes to the source systems.
SAP BW∕4HANA offers flexible ways of integrating data from various sources. The data can be extracted and transformed from the source and load it into the SAP BW system, or directly access the data in the source for reporting an analysis purposes, without storing it physically in the Enterprise Data Warehouse.
a) SAP HANA Source System
- this connectivity can be used for all other databases (e.g. Teradata, Sybase IQ, Sybase ASE).
b) SAP Operation Data Provisioning (ODP)
- acts as the hub for all data flowing into BW from external sources
- used exclusively with SAP Landscape Transformation (SLT), SAP ERP Extractor (SAP Business Suite), HANA Views and SAP BW.
- The PSA no longer exists with the new ODP concept which provides a much faster extraction mechanism.
With those two connectivity types, data can be made available in batch mode, using real-time replication or direct access.
HANA views are automatically generated within the Sap HANA database, after you activate the objects (ex. ADSO, Composite Provider).
As pointed out in connection with LSA++, data processing is much faster with HANA. While data flows were all about streamlining the architecture, there are also a number of tangible benefits in terms of technical performance:
Additionally to classic SAP BW, SAP BW/4HANA offers in memory Data Warehousing:
- No Aggregates or Roll-up Processes
- No Performance specific Objects
- Fewer Indexes
- Faster Loading and Processing
SAP is going in the same direction with the ability to move transformations directly to the database, the so-called push-down.
This performance that SAP BW/4HANA offers is ensured by an algorithm push-down.
This is one of the subjects that we will be discussing in one of our next articles.
Source of images: SAP SE, Inspiricon AG