ETL Fundamentals

ETL service comprises of two parts: Staging engine and Storage Service. Staging engine manages staging process for all data received from several source systems. It interfaces with the AWB scheduler and monitor for scheduling and monitoring data load processes. However, Storage Service manages and provides access to data targets in SAP BW and the aggregates that are stored in relational and multidimensional database management systems.

It is true, however, that the extraction technology provided as an integral part of SAP BW is restricted to database management systems supported by mySAP technology and that it does not allow extracting data from other database systems like IBM IMS and Sybase. It also does not support proprietary file formats such as dBase file formats, Microsoft Access file formats, Microsoft Excel file formats, and others. On the other hand, the ETL services layer of SAP BW provides all the functionality required to load data from non-SAP systems in exactly the same way as it does for data from SAP systems. SAP BW does not in fact distinguish between different types of source systems after data has arrived in the staging area. The ETL services layer provides open interfaces for loading non-SAP data.