Persistent staging area
The Persistent Staging Area ( English for permanent staging area , PSA for short ) is a database table in SAP BW that corresponds to the structure ( transfer structure ) of the interface to the source system (usually a SAP R / 3 system). The data is stored in this table when the data is loaded if this is specified in the settings for the load run ( Processing tab of the InfoPackage ).
The PSA table is created for each data source ( DataSource ) and source system, since the data sources can be structured differently. The source data is stored unchanged in the PSA and only then processed using transfer rules and then made available in a further structure ( transformation ) for loading into the data targets. This means that the original data still exists in BW and can be used to rebuild characteristics ( InfoObjects ), data cubes ( Info providers ) and DSO objects , for example. No new load run from the source system is required. The PSA table can therefore be used as a buffer, but not as a data source that can be accessed directly by evaluations. In addition, manual data cleansing can be carried out in the PSA if incorrect data occurs from the source system .
The PSA table can be deleted at regular intervals by scheduling a deletion process in a process chain. This is done for each data source ( DataSource ) and source system.