In data transfer process (DTP) maintenance, you can specify that data is not extracted from the PSA of the DataSource but is requested straight from the data source at DTP runtime. The Do not extract from PSA but allow direct access to data source indicator is displayed for the Full extraction mode if the source of the DTP is a DataSource. We recommend that you only use this indicator for small datasets; small sets of master data, in particular.
Extraction is based on synchronous direct access to the DataSource. The data is not displayed in a query, as is usual with direct access, but is updated straight to a data target without being saved in the PSA.
If you set this indicator, you do not require an InfoPackage to extract data from the source.
Note that if you are extracting data from a file source system, the data is available on the application server.
Using the Direct Access mode for extraction has the following implications, especially for SAP source systems (SAPI extraction):
● Data is extracted synchronously. This places a particular demand on the main memory, especially in the source system.
● The SAPI extractors may respond differently than during asynchronous load since they receive information by direct access.
● SAPI customer enhancements are not processed. Fields that have been added using the append technology of the DataSource remain empty. The exits RSAP0001, exit_saplrsap_001, exit_saplrsap_002, exit_saplrsap_004 do not run.
● If errors occur during processing in BI, you have to extract the data again since the PSA is not available as a buffer. This means that deltas are not possible.
● In the DTP, the filter only contains fields that the DataSource allows as selection fields. With an intermediary PSA, you can filter by any field in the DTP.