Bridge the Gap to Better Business Intelligence with SAP BW Bridge!
The BW Bridge is presented by SAP as a way to transfer a system from a classic on-premise environment to the SAP Datasphere (formerly Data Warehouse Cloud). This interview was conducted by Daniel Moser (Senior Account Manager, s-peers AG) with Eugen Gering (Data Warehousing Experts-peers AG) and sheds light on the functions of the SAP BW Bridge, its architecture and its advantages and disadvantages with the following seven questions.
Table of contents
Hello Eugen, first of all thank you for being available for this interview. At s-peers AG, you are an expert in the field of data warehousing and in particular for BW Bridge. BW Bridge has been around for almost a year now, and a lot has happened in the product development of BW Bridge. I would like to take this as an opportunity to ask you seven questions about BW Bridge, so that BW can turn "old" into "new". So that everyone has the same level of knowledge about the BW Bridge, I would like to ask you first a comprehension question about the BW Bridge:
Question 1: What is the BW Bridge?
The BW Bridge, which will be published in November 2021, is a functional extension of SAP Datasphere (formerly DWC), which was previously not compatible with old developments from the classic BW system. With the so-called BW/4HANA Model Transfer, Datasphere offers the option of transferring the semantic layer to Datasphere on the basis of queries and using it in hybrid use of both systems. However, until now it was not possible to transfer persistent objects and transformation logics specifically with customer-specific ABAP routines to Datasphere and to use them independently of the on-premise system.
This is now possible with BW Bridge!
Eclipse, already familiar from the classic on-premise BW world, serves also as the development environment for the BW Bridge, in whichclassic BW objects such as DataStore objects (advanced), transformations, DataSources, process chains, etc. can be created. Developments using ABAP are also possible.
A list of other important BW Bridge features including explanations is provided in the following knowledge article here.
Question 2: How is the BW Bridge structured?
The BW Bridge user interface consists of the SAP BW Bridge Cockpit and the ABAP Admin UI. In Eclipse, development can be done using the BW Modeling Tools and ABAP Development Tools add-ons.
The figure below also shows that the BW Bridge only allows SAP products that can be connected via ODP as data sources. Non-SAP systems can still be connected directly in the Datasphere (formerly DWC) via the many integration options.
The connection between the BW Bridge and the Datasphere takes place via a separate Space, which enables the data to be shared with other Spaces via the share function.
Figure 1: User interface of the BW Bridge, source: SAP blog
Question 3: What is the path via the BW Bridge into SAP Datasphere?
Figure 2: The on-premise path of the BW Bridge, source: SAP blog.
With the described function extension, BW Bridge also offers a path from the on-premise system to the public cloud. During the conversion, existing data flows including DataSource, transformations, ABAP code, InfoObjects, etc. can be transferred under certain conditions. Queries are transferred, but cannot be executed as in the classic BW system or used as a source for other data targets. This is due to the lack of support for OLAP functionalities.
Question 4: How does the conversion from the BW system to BW Bridge work?
SAP offers two different conversion tools to transfer BW objects from an on-premise system to the public cloud of the BW Bridge. While the shell conversion requires the data to be reloaded after conversion, the remote conversion transfers existing data at the same time.
During shell conversion, the metadata of the selected objects is converted from the existing on-premise system to the BW Bridge. No data itself is transferred, only the definition of the objects. Due to the possibility of developing with ABAP in the BW Bridge, ABAP logic that has already been developed can continue to be used in the Datasphere.
The data itself can then be loaded manually from the ODP source system in BW Bridge.
In addition to the metadata of the selected objects, the remote conversion also transfers the existing data. This is particularly useful for data models that cannot receive historical data from the source system or cannot be initialized for technical reasons.
Question 5: What are the implementation challenges?
According to SAP, the BW Bridge is the path from an on-premise system to the cloud. However, the use of the function extension is characterized by many restrictions.
For example, compatibility is severely limited: When converting, it should be noted that no function modules and no classic programs can be created, since the BW Bridge only allows class-based program code.
If queries are also transferred from the on-premise system, they cannot be executed on the BW Bridge. The transfer of these queries via the BW/4HANA Model Transfer is associated with further restrictions at the current stage of development.
As an integrated part of SAP Datasphere, BW Bridge uses the main storage of the cloud application. Therefore, another limitation when using the BW Bridge is the limited storage space, which is usually much smaller compared to an on-premise system.
File interfaces or sources that are connected via HANA or SDI/SDA cannot be imported into BW Bridge.
There are no OLAP functions in the BW Bridge, so that, for example, queries cannot be transferred as InfoProviders for other data targets.
HANA native developments or mixed modeling scenarios, e.g. the use of HANA CalcualtionViews in the BW system, cannot be transferred to the BW Bridge using conversion tools.
Up to now, there is also no possibility to connect the SAP GUI of SAP Datasphere with the BW Bridge.
These restrictions apply to the current version in August 2022. It should be noted that the product is constantly being further developed by SAP and that these restrictions may therefore change on an ongoing basis.
Question 6: What are the advantages of BW Bridge?
Even if the conversion of an entire BW system to the BW Bridge is difficult due to the numerous restrictions mentioned above, it can still be used to transfer individual parts from an on-premise system to the cloud.
When converting to the cloud system, the following objects, among others, known from the BW system, can be transferred:
- Data Source (ODP)
- Advanced Data Store Objects (ADSO)
- Data transfer processes (DTP)
- ABAP Extensions/Code
- Source systems (SAP)
In addition, ABAP code can be used in the Eclipse environment, which was previously not possible in the DWC.
Using the BW Bridge also makes it possible to activate old SAP content so that it can then be used in the Datasphere. This is an advantage in that the content in the BW system is usually more powerful than that offered in the Datasphere. In addition, the possibility of developing with ABAP means that the range of functions in the Datasphere can be extended to include this programming language. These points can also be used independently of a transfer of an existing on-premise system.
Question 7: How innovative is the BW Bridge?
As one of SAP's newest features, BW Bridge is definitely innovative as it extends Datasphere with classic BW objects and also enables restrictive migration from an on-premise system. So far, however, there are many challenges in the project of transferring an entire BW system to the BW Bridge due to these restrictions.
However, it is to be expected that SAP willcontinue to develop theproduct inthis respect, so that certain restrictions should no longer apply in the future.
For example, it has already been announced that it may be possible in the future to transfer Datasphere-models back into the BW Bridge.
We are happy to support you in analyzing your current on-premise system and work with you to develop possible use cases that can be implemented with BW Bridge and Datasphere in the next step.
Would you like to delve deeper into the topic of BW Bridge or activate BW Bridge together?
I look forward to hearing from you!