Want to understand SID concept...

Hello experts,

why not using the value like e. g. customer number directly in the dimension table instead of a SID? So I also could save one table (SID table) and with this on JOIN by linking directly to the master data tables (text, attributes, hierarchies) using customer no. as key.

Am I wrong? Is it only because of this INT4 thing with the SIDs whitch maybe results in better performance?

What I maybe understand is compounding, it seems to be hard to make here a connection to the right master data table. But if I wouldn't have this case, why else could be this SID useful?

Best regards,

Peter