I know where to link. What I want to know is if I'll have a best performance (considering processing time, space used, etc) creating a new table and linking it with the fact or put the information on the fact table (table "Fato"). What I'm worried about is that if I put the information on fact table, I'll have a lot of null values on table (useless allocated space) and if I create a new table, I'll not spend space, but probably I'll need more data processing.
I think null values will not take up space. I find the best solution often to be to concatenate the new data into the fact table. Best way forward is probably to make a quick test of both (or all three) scenarios and see which is best.
Whithout knowing the number of rows, distinct values etc it is difficult to advise.