A data transfer process (DTP) is an object that determines how data is transferred between two persistent objects in SAP NetWeaver BW.
You use the data transfer process to transfer data in SAP NetWeaver BW from one persistent object to another object, in accordance with certain transformations and filters. In this respect, it replaces the data mart interface and the InfoPackage. As of SAP NetWeaver 7.0, the InfoPackage only loads data to the entry layer of SAP NetWeaver BW (PSA).
The data transfer process makes the transfer processes in the data warehousing layer more transparent. Optimized parallel processing improves the performance of the transfer process (the data transfer process determines the processing mode). You can use the data transfer process to separate delta processes for different targets and you can use filter options between the persistent objects on various levels, between a DataStore object and an InfoCube for example.
Data transfer processes are used for standard data transfer, for real-time data acquisition, and for accessing data directly.
The following graphic illustrates how the data transfer process is positioned in relation to the objects in the dataflow and the other objects in SAP NetWeaver BW process control:
The InfoPackage controls the transfer of data from the source to the entry layer of SAP NetWeaver BW. The data transfer process controls the distribution of data within SAP NetWeaver BW. The graphic illustrates an example of a data update from the DataSource to an InfoProvider. The data can be updated from one InfoProvider to another using a data transfer process. The data transfer process can also be used to control data distribution from a BW system to any target outside of SAP NetWeaver BWI. A data transfer process with an open hub destination is used as the target for this.
You use a process chain to define a data transfer process. Alternatively, you can define a data transfer process for an InfoProvider in an object tree in the Data Warehousing Workbench. We recommend using process chains. In this case, the data transfer process is executed when it is triggered by an event in the predecessor process in the process chain. Alternatively, in process chain maintenance, you can execute a data transfer process in the background. A debug mode is also available.
The request is an instance that is generated at the runtime of the data transfer process. The request is processed in the steps that have been defined for the data transfer process (extraction, transformation, filter and so on). The monitor for the data transfer process request shows the header information, request status, and the status and messages for the individual processing steps.
With a data transfer process, you can transfer data either in full extraction mode or in delta mode. In full mode, the entire dataset of the source is transferred to the target; in delta mode, only the data that was posted to the source since the last data transfer is transferred. The data transfer process controls delta handling and therefore allows you to fill several targets with different deltas from one source. With a data transfer process, you do not need to explicitly initialize the delta method as you do when copying data with an InfoPackage.
The data transfer process supports you in handling data records with errors. When you define the data transfer process, you can determine how the system responds to errors. At runtime, the incorrect data records are sorted and written to an error stack (request-based database table). A special error DTP further updates the data records from the error stack into the target. It is easier to restart failed load processes if the data is written to a temporary storage after each processing step. It also allows you to find records that have errors. In the monitor for the data transfer process request or in the temporary storage for the processing step (if filled), you can display the data records in the error stack . In data transfer process maintenance, you determine the processing steps after which you want to store data temporarily.
Note also the tips for optimizing DTP performance. More information: Performance Tips for Data Transfer Processes.