Layers Of Sap Netweaver Bw

The SAP Business Warehouse has many layers that are responsible for true data acquisition and information processing in line with immense analytical capabilities. According to the features and applications in the software, the different layers in SAP BW are:

A) Extraction layer
B) Staging layer
C) Transformation layer
D) Loading layer
E) Reporting and analysis layer

A) Extraction layer:
The extraction layer is the collecting of data from source systems. It strives to secure the integrity of data while eliminating reporting problems on the source systems. Data can be extracted from an array of different sources.
SAP NetWeaver BW offers predefined, customizable extractors for application data from the entire SAP Suite. You can also design extractors for customized SAP applications. Most extractors for SAP application transaction data are delta-enabled, which signifies that transactions can be written to a delta queue at the time of posting. They are then extracted from this delta queue into SAP BW.
Direct extraction from databases based on table or view definitions using DB Connect and UD Connect extraction interfaces. DB Connect (Database Connection) permits the extraction from and direct usage of data lying in tables or views of database management systems. This feature is available primarily for some specific databases. UD Connect (Universal Data Connect) permits the extraction
from and direct access to both relational and multidimensional data.
Web services allow you to push data to the SAP BW system with external control.
Flat file interface allows extraction from flat files in ASCII and CSV format.
Staging BAPIs (Staging Business Application Programming Interfaces) are open interfaces from which third-party tools can extract data from prior systems. The data transfer can be triggered by a request from the SAP BW system or by a third-party tool.
Data is acquired from SAP BW using a pull mode, through objects called InfoPackages. Parameters for the data acquisition can be set in the InfoPackage.

B) Staging layer:
Extracted data is received and briefly stored in the staging layer of SAP NetWeaver BW. The data staging layer stores source data from diverse operational sources. When data is inside of the staging layer all needed transformations can then occur while not interfering with the operations in the source systems. Data is also preprocessed for purifying before calculation and/or aggregation based on business requirements. This layer is mostly represented by the persistent staging area (PSA), where data is stored in SAP BW just after it's extracted. The technical structure of a PSA is contingent on the structure of the DataSource.

C) Transformation layer:
The transformation layer of SAP BW facilitates the consolidation, cleaning, and integration of data into the warehouse. Data gets tailored from the source data format into the desired destination data format. Data transformation can include data mapping and formulas.

D) Loading layer:
The actual process of pushing data through the transformation layer into the data targets. A data transformation process (DTP) transforms the data based on the parameters determined between the DataSource and the data target.

E) Reporting and Analysis layer:
Within the reporting and analysis layer, reports and dashboards are created to display data in a format where analysis can be done. The components that signify the reporting and analysis layer are organized together in the SAP business explorer (BEx) toolset and more recently the Business Objects toolset.