Structure of the VirtualProvider with Data Transfer Process
This type of VirtualProvider is defined based on a DataSource or an InfoProvider and copies its characteristics and key figures. Unlike other VirtualProviders, you do not need to program interfaces in the source system. To select data in the source system, you use the same extractors that you use to replicate data into the BW system. When you execute a query, every navigation step sends a request to the extractors in the assigned source systems. The selection of characteristics including the selection criteria for these characteristics is transformed according to the transformation rules for the fields of the transfer structure. They are passed to the extractor in this form. The delivered data records pass through the transfer rules in the BW system and are filtered again in the query.
Since hierarchies are not read directly by the source system, they need to be available in the BW system before you execute a query. You can access attributes and texts directly.
If the DataSource has an enhancement, this will not run during direct access. This means that fields added to the DataSource will not be filled with data.
Currently, the transformation only supports inverse transformations for direct assignment (without conversion routine) and the expert routine. Inverse transformations for other routine types and other rule types are also not yet implemented.
With more complex transformations such as routines or formulas, the selections cannot be transferred. It takes longer to read the data in the source system since the amount of data is not restricted. To prevent this, you can create an inversion routine for every transfer routine. Inversion is not possible with formulas. We therefore recommend using routines instead of formulas.