SOAP-Based Transfer of Data 
Purpose
As a rule, data transfer in BW takes place using a data request that is sent from BW to the source system (pull from the scheduler). You can also send the data to SAP BW using an external control. This is a data push into SAP BW.
Data push is possible for multiple scenarios:
· Transferring Data Using the SOAP-Service des SAP Web AS
· Data Transfer Using Web Service
In all three scenarios, data transfer takes place via transfer mechanisms that are sufficient for Simple Object Access Protocol (SOAP) and are XML based.
The SOAP-based transfer of data is only possible for flat structures. You cannot transfer hierarchy data.
Process Flow
The data push takes place in an inbound queue in SAP BW. SAP BW uses the delta queue of the service API as the inbound queue. To transfer the data, you generate a DataSource based on a file DataSource that has an interface for supplying the delta queue. The system generates an RFC-enabled function module for this so-called XML DataSource. This runs the data update in the delta queue for the XML DataSource. A prerequisite for updating to the delta queue is that you have activated the data transfer to the delta queue beforehand.
In order to enable a data push into SAP BW using one of the three scenarios listed above, follow the steps below:
...
1. Create the XML DataSource.
a. Create an InfoSource with flexible update and generate a file DataSource for it.
b. Based on the file DataSource, generate an XML DataSource.
2. Activate the data transfer to the delta queue of the XML DataSource by initializing the delta process for the XML DataSource.
Result
You can use one of three scenarios listed above to save the data to the delta queue in SAP BW. From there you can collect data using the usual staging methods for deltas in SAP BW and then update it to the data targets.
The following graphic shows how data can be transferred to the SAP BW delta queue using a push in the delta process. For larger volumes of data, we recommend that you load the data using a full upload to the file DataSource. After the push, the data is checked for syntactic correctness and is converted into ABAP fields and then stored and collected in the delta queue of SAP BW: There the data is available for further processing in SAP BW.
