Step-by-step control flow for a successful data extraction with SAP BW:

   1.  An InfoPackage is scheduled for execution at a specific point of time or for a certain system- or user-defined event.

   2.  Once the defined point of time is reached, the SAP BW system starts a batch job that sends a request IDoc to the SAP source system.

   3.  The request IDoc arrives in the source system and is processed by the IDoc dispatcher, which calls the BI Service API to process the request.

   4.  The BI Service API checks the request for technical consistency. Possible error conditions include specification of DataSources unavailable in the source system and changes in the DataSource setup or the extraction process that have not yet been replicated to the SAP BW system.

   5.  The BI Service API calls the extractor in initialization mode to allow for extractor-specific initializations before actually starting the extraction process. The generic extractor, for example, opens an SQL cursor based on the specified DataSource and selection criteria.

   6.  The BI Service API calls the extractor in extraction mode. One data package per call is returned to the BI Service API, and customer exits are called for possible enhancements. The extractor takes care of splitting the complete result set into data packages according to the IDoc control parameters. The BI Service API continues to call the extractor until no more data can be fetched.

   7.  The BI Service API finally sends a final status IDoc notifying the target system that request processing has finished (successfully or with errors specified in the status IDoc).

Note

Control parameters specify the frequency of intermediate status IDocs, the maximum size (either in kilobytes or number of lines) of each individual data package, the maximum number of parallel processes for data transfer, and the name of the application server to run the extraction process on.