Importance of semantic groups in DTP

Semantic Groups to specify how you want to build the data packages that are read from the source (DataSource or InfoProvider). To do this, define key fields. Data records that have the same key are combined in a single data package. 

This setting is only relevant for Data Store objects with data fields that are overwritten. This setting also defines the key fields for the error stack. By defining the key for the error stack, you ensure that the data can be updated in the target in the correct order once the incorrect data records have been corrected.

A very simple example:

Lets say there are two records in the input stream of data for a DTP.

Product   Material 

P1           M1 XYZ 

P1           M1 PQR 

If the data gets divided into multiple packets while getting processed, the above two records might go into separate data packets. In case you have defined semantic group in DTP with product and material, system will always put these two records together. This is sometimes required when it is needed to process all such records together, for eg., in start routine.

Semantic Groups are to specify how you want to build the data packages that are read from the source. To do this, you determine key fields. Data records that have the same key are combined in one data package. Currently, only data that has been read from the PSA can be processed further in semantic groups.

This setting also determines the key fields for the error stack. 

In bw3.x infopackage directly transfers the data to targets but in BI 7 infopackage will only bring data to PSA, Data Transformation Processing will transfer the data from PSA tothe target. PSA is only staging area this will not be a target (we can’t do anything here)