If you are already working in S4 HANA projects or if you are upskilling yourself in S4 HANA, I’m sure that you have heard the term Universal Journal or Single Source of truth. But, what is that actually? Trust me, as a S/4 HANA consultant, we must understand ACDOCA table in a better way. In my experience of 3 S/4 HANA transformation projects, I have learnt a lot about this table and I don’t think I’m finished yet. In my next series of blogs, we will discuss ACDOCA innovations. As always, this is a techno-functional blog series, created for both technical and functional consultants. I have divided this blog series into 3 blogs.
Part 1 covers Technical Aspects
Part 2 covers Functional Aspects
Part 3 covers Reporting & Analytics
- Simplified Data Model
Earlier SAP versions use total tables & index tables to store data for faster retrieval. But in S4 HANA, aggregations or calculations can be performed on the fly from ACDOCA, so there is no need to store the same data again in other tables. SAP removed all total & index tables, hence removed duplicate data from the DB. Data from all modules in FI & CO is now collected in ACDOCA, and so it is called Universal Journal. In the diagram below, all Total & Index tables in yellow color have been removed from DB.
- Engineered to make the most of HANA DB
ACDOCA makes use of all HANA DB innovations.
– Data layout in the main memory
– Partitioning & parallel processing
Data is stored in columnar structure, so when a query is run on ACDOCA, it is not necessary to read the complete row, and data is quite easily transferred to CPU from main memory. Column based data storage is nothing new, it was already there in Data Warehouse applications. SAP HANA’s compression techniques are very efficient with regard to runtime, and can provide an average compression factor of five to ten compared to data that has not been. Hence, it minimizes the amount of data that needs to transferred to CPU. SAP HANA supports only horizontal partitioning, means the data is partitioned into smaller sections on row basis. A search operation is performed on all the partitions in parallel resulting faster data retrieval
- Indexing on ACDOCA
Thanks to data compression, a relatively small volume of data needs to be
searched, and the search mainly compares integers. Since you can parallelize the search across multiple CPU cores, the speed is usually sufficient, and an index is not required. In the case of tables with fewer than half a million entries, there is very little difference between having an index and not having an index. If, on the other hand, the table has hundreds of millions of entries, accessing a highly selective column without an index is slower by a factor of 100 or more compared to accessing it with an index. This factor increases as the table grows in size. If such an access is performed very frequently, as may be the case, in an OLTP system, for example, an index is vital for good performance. In S4 HANA, indexes are generally created on a single column and called as inverted index. Index on multiple column is also possible and that is called composite index. Only inverted indexes are available in standard and all of them are HANA DB specific only.
- Compatibility Views
Now you must be thinking what will happen to my custom codes where I have an explicit select from those total or index tables. Don’t worry. With the installation of SAP Simple Finance, on-premise edition totals and application index tables were removed and replaced by identically-named DDL SQL views, called compatibility views. These views are generated from DDL sources. This replacement takes place during the add-on installation of SAP Simple Finance using SUM – related
data is secured into backup tables. The compatibility views ensure database SELECTs work as before. However, write access (INSERT, UPDATE, DELETE, MODIFY) was removed from SAP standard, or has to be removed from custom code – refer to SAP note # 1976487.
- Amount Fields length extension
In SAP S/4HANA, currency amount fields with a field length between 9-22 including 2
decimals have been extended to 23 digits including 2 decimals. In addition to currency
amount fields, selected data elements of DDIC type DEC, CHAR, and NUMC with
varying lengths and decimal places that may hold amounts have been affected. This
feature is available in SAP S/4HANA, on-premise edition 1809 and higher releases.
The amount field length extension was developed to meet the requirements of banks and
financial institutions to post financial documents representing balance sheet information
with amounts that exceed what the previous definition in SAP ERP ECC60 and previous
S/4HANA releases support. Therefore, we extended the amount fields within the general
ledger and Controlling application areas. As part of these changes, we changed data
elements of other application components with shared dependencies.
The fields that were subject to extension were primarily data elements of type CURR
with a defined length between 9 and 22, including 2 decimal places. Additionally, data
elements of type DEC, CHAR, and NUMC that were used to store amounts were also
To facilitate the correct handling of the extended amount fields within the ABAP coding,
the specific circumstances and requirements of each possible scenario were
considered. Overflow errors could occur if an extended amount is moved into a shorter
amount. Syntax errors and report generation errors can be identified though S/4HANA
Readiness code scans.
- ACDOCA Extensibility
It is possible to add custom fields in ACDOCA, refer to SAP note # 2453614
- BSEG – A cluster table to transparent table
BSEG was a cluster table in R3 because of the limitation of Oracle DB. It has been converted to transparent table in S4, as there is no need of pooled & cluster tables on HANA DB. This does not require any change to the application. However, we should not rely on Database Interface to do the sorting automatically, which was the case for pooled & cluster tables. If you have relied on this behavior, you must add explicit sort statement in your custom program.
Stay tuned for the other blog coming up on this series. Thank you for reading. Let’s keep learning together.