In the data transfer process (DTP) maintenance screen, you can specify that data is not extracted from the Persistent Staging Area (PSA) of the DataSource. Instead the data is requested directly from the data source at DTP runtime and then transferred to the InfoProvider. It is not necessary to load the data into the PSA beforehand, using an InfoPackage.
The flag Do not extract from PSA; use direct access to data source is displayed if the DTP source is a DataSource and the source system is an operational data provisioning (ODP) source system. Using the ODP data replication interface and this function allow you to extract mass data. If the source can return deltas, then extraction is also supported in delta mode.
Note the following:
Direct loading in Full mode is supported for the ODP contexts SAP HANA and SAP Business ByDesign. These contexts do not offer any deltas in the source.
If errors occur during processing, you need to extract the data again in BW because the PSA is not available in the buffer.
For Delta DTPs: Only the last successfully updated request of a delta DTP can be deleted. In other words, the requests of a delta DTP can only be deleted in strict reverse chronological order.
For delta DTPs: in the delta queue of the source system, the data is deleted during delta queue reorganization after a certain retention period has elapsed and after the data has been updated to the BW system. When deleting requests in the InfoProvider, you should therefore bear in mind that you might not be able to retrieve the data from a request in the source system any more. If the data of deleted requests in the delta queue can no longer be retrieved, you have to delete all the delta requests of the same DTP from the InfoProvider and execute a new delta request, in order to start delta initialization.