This is yet another question that I get from all angles, partners, customers but even colleagues. BW has been the spearhead SAP application to run on HANA. Actually, it is also one of the top drivers for HANA revenue. We've created the picture in figure 1 to describe - on a high level - what has happened. I believe that this not only tells a story on BW's evolution but underlines the overall HANA strategy of becoming not only a super-fast DBMS but an overall, compelling and powerful platform.
Fig. 1: High level comparison between a classic BW and the two versions of BW-on-HANA. Here as PPT.
Classic BW (7.3ff) follows the classic architecture with a central DBMS server with one or more application servers attached. The latter communicate with the DBMS in SQL via the DBSL layer. Features and functions of BW - the red boxes in the left-most picture of fig. 1 - are (mostly) implemented in ABAP on the application server.
BW 7.3 on HANA
At SAPPHIRE Madrid in November 2011, BW 7.3 was the first version to be released on HANA as a DBMS. There, the focus was (a) to enable HANA as a DBMS underneath BW and (b) to provide a few dedicated and extremely valuable performance improvements by pushing the run-time of certain BW features to the HANA server. The latter is shown in the centre of fig. 1 by moving some of the red boxes from the application server into the HANA server. As the BW features and functions are still parameterised, defined, orchestrated from within the BW code in application server, they are still represented as striped boxes in the application server. Actually, customers and their users do not note a difference in usage other than better performance. Examples are: faster query processing, planning performance (PAK), DSO activation. Frequently, these features have been implemented in HANA using specialised HANA engines (most prominently the calculation and planning engines) or libraries that go well beyond a SQL scope. The latter are core components of the HANA platform and are accessed via proprietary, optimised protocols.
BW 7.4 on HANA
The next step in the evolution of BW has been the 7.4 release on HANA. Beyond additional functions being pushed down into HANA, there has been a number of features (pictured as dark blue boxes in fig. 1) that extent the classic BW scope and allow to do things that were not possible before. The HANA analytic process (e.g. using PAL or R) and the reworked modeling environment with new Eclpise-based UIs that smoothly integrate with (native) HANA modeling UIs andconcepts leading also to a reduced set of infoprovider types that are necessary to create the data warehouse. Especially the latter have triggered comments like
- "This is not BW."
- "Unbelievable but BW has been completely renewed."
- "7.4 doesn't do justice to the product! You should have given it a different name!"
It is especially those dark blue boxes that surprise many, both inside and outside SAP. It is the essence that makes dual approaches, like within the HANA EDW, possible, which, in turn, leads to a simplified environment for a customer.