you better do use DSO, Becoz IN Dtp level, Semantic groups are defined as Key fields.
Semantic groups can be used for , records with the same key are combined with sequential order ( Records )in a single data package .
IN DSO
M1 100
M2 200
M1 300
Semantic key can be used, records are saved in Data package this format
m1 100
m1300
m2 200
new table is activted
data is stored in M1 300 active table data is over writes
M2 200
records are stored in sequential order
In info cube semantic key is not used . info cube is aggregated data
m2 200
m1 300
Semantic key can be only applicable in DSO DTP level