Traditional systems relied on inflexible models, precomputed data, and slow computational systems. By eliminating things such as needleless duplication and precomputation of data which clogs other systems, we have significantly lowered your cost of managing Financials.
And because our experience at building robust accounting systems, we can do this without disruption to your business. By freeing your system of the constraints of precomputed data models, we also open up your system to a more agile way of computing, allowing financial analysts to quickly experiment with what-if models while speeding quarterly closes.
This blog post is the first of a series that dives deeper into various aspects of SAP Simple Finance and their technical underpinnings. Recently, Hasso Plattner wrote about the impact of aggregates and explored the negative impact of materialized aggregates and why relying on them for performance severely restricts flexibility.
Generally speaking, the generic term materialized view and the special case materialized aggregate refer to the physical storage of derived and redundant data in a database. In this deep dive, we look closer into the technical foundations and highlight the positive impacts that can be realized when removing materialized views. We are going to explore why materialized views and materialized aggregates are no longer necessary and how removing redundant data storage in a non-disruptive manner improves transactional throughput and lowers storage costs without compromising analysis performance.
In this blog post, we focus on the non-disruptive changes to the data model that removed redundancy from SAP Simple Finance and why switching to Simple Finance is possible in an entirely non-disruptive manner. In the next two blogs we will investigate the concepts of materialized views and materialized aggregates, respectively, and demonstrate that it is indeed feasible with in-memory database systems to get rid of these redundant constructs.
Future parts of the deep dive series will also highlight additional improvements and paradigms of Simple Finance that are possible thanks to SAP HANA and focus on, for example, the business value associated with Simple Finance, non-disruptive innovation, and how Simple Finance enables decision makers to overcome aggregate information loss. In this first part of the series, we begin with exploring the concept of redundancy in general.
Afterwards, we look deeper into the changes of the data model brought with Simple Finance and highlight how this non-disruptive innovations has been possible, allowing an almost seamless switch-over to SAP Simple Finance. We demonstrate the positive impact of the new data model on database footprint and transactional throughput. While we focus on the Financial Accounting component, other components such as Management Accounting Controlling have similarly been changed, so our comments apply to Simple Finance as a whole.
Redundancy is a frequent source of inconsistency and anomalies. As redundant data needs to be kept in sync on updates, redundancy in a data model leads to slower updates. To reduce redundancy, database normalization techniques such as normal forms have been introduced Codd: Historically, redundant data has nevertheless often been stored explicitly only to improve read performance, as the calculations to derive it in the absence of materialization required too much additional effort.
For years, enterprise applications have employed redundant data storage in order to provide sufficient performance to users in transactional and analytical applications alike. The limited performance of traditional, disk-based database systems required redundantly kept data that could be accessed quickly, but needed to be updated and kept in sync with transactional changes. In view of millions or billions of accounting documents headers, stored in table BKPF and their line items table BSEG , materialized views and aggregates as mechanisms to maintain redundant data provided fast access to items with specific properties.
Thus, SAP Simple Finance overcomes the associated costs such as reduced transactional throughput and increased database footprint. At the same time, SAP Simple Finance is a non-disruptive innovation of the classical ERP Financials because it replaces the materialized views with non-materialized compatibility views.
All applications that have read from the materialized views, be it SAP standard reports or customer modifications, continue to access the views as before without requiring any changes. Although these are already big breakthroughs, the most important advantage of SAP Simple Finance is the dramatically improved flexibility that, for example, encourages exploring the data according to various analysis needs and contributes to the success of Simple Finance as an information system.
A follow-up blog post will elaborate on the business value that can be realized thanks to the gain in flexibility and the simplification. These compatibility views transparently provide access to the same information calculated on the fly to ensure that the changes are non-disruptive.
In addition to removing the materialized views, SAP Simple Finance also evolves the traditional Financials data model by removing the materialized aggregates from the system, again replacing them by compatibility views.
In the end, the transactional data model of core Financial Accounting — besides master data — consists only of the essential accounting document header BKPF and accounting document line item tables BSEG.
All the other tables mentioned on the left side of the following Figure 1 are then obsolete. Instead, transparent access to exactly the same information is provided on-the-fly by equally named compatibility views, as outlined on the right side of Figure 1.
It offers rich modification options to customer to adapt the system to their needs, including custom modifications. Changes to the core data model need to take this into account. They have to be non-disruptive with regard to the large amount of code by SAP and its customers that builds on top of the data model. To ensure adoption of the benefits of SAP Simple Finance, all innovations have been implemented in a non-disruptive manner.
Switching to SAP Simple Finance does not require updating any custom coding for reading from the database. So-called compatibility views have been the means to achieve this non-disruptiveness: As it has the same name and is transparently accessed via the data dictionary, existing applications that so far relied on the materialized view for accessing items or aggregates do not experience any difference.
They continue to work as before without any changes to the code. For example, a query accessing BSID has previously read the value from the materialized view. Now, the same access to BSID is resolved into a query using the view definition and calculated on-the-fly. The result is the same in both cases. As the calculations have demonstrated, this is feasible without compromising performance.
As a consequence of the non-disruptive innovation, all of the benefits associated with Simple Finance — such as increased throughput, flexibility, and reduced database size — are available at no adaptation costs to customers — a migration of the database mostly removing the redundant tables is sufficient.
A future deep dive will look into non-disruptive innovation and the technology of compatibility views in more detail. As a benefit of the non-disruptive nature of the above-mentioned changes, code changes in the Financials component done by SAP were only necessary to remove the now unnecessary writing operations to former materialized views and aggregates when posting accounting documents.
This includes code pushdown of data-intensive logic to the database and backend decoupling for new Web-based user interfaces SAP Fiori. Reduction of Database Footprint The removal of both materialized views and materialized aggregates significantly reduces the database footprint of Financials that has been occupied by redundant data.
In an exemplary system from an SAP customer, the total size occupied by the set of core tables for financial accounting is reduced by a factor of 6. For details, please refer to the following table that includes a non-exhaustive list of tables that have been replaced by compatibility views.