Creating Transformations and Data Transfer Processes

Now we have DataSources for attributes and texts in SAP BW/4HANA, we can complete the master data flow with the master data-bearing Characteristic U##_COSTC as a target. We will set up a Transformation (logic to derive the value of the target fields) and Data Transfer Process (definition how and which data is transferred) for both DataSources.

For the Transformation, we are trying to keep things simple. Because we added a custom global transfer logic directly to our InfoObject U##_COSTC, we just need field-to-field mapping for the InfoObjects (the rules will be of the Direct Assignment type). If we would not have used a global transfer routine on our InfoObject U##_COSTC, we would have had to maintain the same rule for U##_COSTC in every single Transformation.

Regarding the Data Transfer Process, no filters are defined and a full load of data is used.

A Transformation is an SAP BW/4HANA object with the mapping between source and target fields, where a rule can be defined for each mapping, which can be used to change the content of the field for each data record that is transferred.

You can create the SAP BW/4HANA transformation using the Context menu within the Data Flow object. You can also create SAP BW/4HANA transformations using the context menu of the target.

In a Transformation, source fields can be used . In the picture above, the source fields from SAP S/4HANA have technical names that are based on German names (for example BUKRS), and the target fields are InfoObjects, which are mainly based on Business Content InfoObjects. These InfoObject start with 0, and are based on English names (for example 0COMP_CODE).

A Data Transfer Process (DTP) is an SAP BW∕4HANA object that determines how and which data is transferred between a source and target object.

The Data Transfer Process defines how to transfer data within SAP BW/4HANA from one persistent object to another, in accordance with certain transformations and filters. At least one DTP is required, but it's possible to define multiple ones. For example, to load the data in multiple loads using filter criteria.

The Data Transfer Process makes the transfer processes in the data warehousing layer 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 two DataStore Objects (advanced), for example. Data Transfer Processes are used for standard data transfer, for real-time data acquisition, and for accessing data directly.

If required, you can define filter criteria for each Data Transfer Process. This means that you can use multiple Data Transfer Processes with different selection criteria to efficiently transfer small sets of data from a source into one or more targets, instead of transferring large volumes of data. You can specify single values, multiple selections, intervals, selections based on variables, or routines. Choose Change Selection to change the list of InfoObjects that can be selected. The icon next to the button indicates that predefined selections exist for the Data Transfer Process. The tool tip for this icon displays the selections as a character string.

With a Data Transfer Process, you can transfer data either in full extraction mode or in delta mode. In full mode, the entire data set 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.

The Data Transfer Process helps you to handle data records with errors. When you define the Data Transfer Process, you can determine how the system responds to errors. At run time, 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.