With the availability of new extraction services (ODQ), the persistence staging layer (PSA) has become obsolete in SAP BW4HANA.
The data is loaded to Advanced DSO directly, without loading to PSA.
A decision has to be made whether to use source fields or build InfoObjects first and use them in Advanced DSO.
For incorporating transaction data into advanced dso following rules apply:
- If there is an infoobject for the filed – a distinction has to be made for below scenarios-
- Use infoObject if the field is core field (e.g. MATNR -> 0MATERIAL)
- Use infoObject is field requires referential integrity
- Use infoObject is you required to built hierarchy on that field
- If you are not sure of the field assignment, do not use infoObject, use field instead.
2. If there is no infoObject for a field, a distinction can be made between following scenarios:
- The field is of type characteristic and having no attributes e.g. Name of Customer, this remains a field. No infoObject modeling is performed. The semantics are defined in reusable Open ODS view or Composite Provider
- The field is of type key figure, there is a possibility of another field having unit or currency information. This remains as a field, No infoObject modeling is performed. The mapping to unit or currency is defined in Open ODS view or Composite Provider
- The field contains text information, this cause redundancy in transaction data, this should be dealt in external master data
- The field is characteristic like and having its own attributes e.g. Product. This is also an external source of master data.
Once the data is there in an advanced dso in propagation layer, an Open ODS view of type Facts is built on top of it and mapping to infoObject is defined if applicable and assignment to Open ODS views of type master data.
There is also option to built composite provider of course.
Thus the advanced DSO can be part of Open ODS layer (here the mapping from datasource will be 1:1)
or the advanced DSO can be part of propagation layer where the data is stored harmonized and of high quality.
In both cases, semantic modeling is performed using Open ODS views or if applicable, in the Composite Provider.