source system ids

hi folks

in the standard infocube, i can find many repetitions...

for example, Logical procurement system has two objects, also theres a source system of the partner, then theres a product id object and just a product object (apart from a product description object)

and then product category and product category id objetcs...which to include out of these many repetitions considering theres only one backend system....

appreaciate all ur inputs, thanks