I’ve made this simple web-based closed cube drawing tool to explain what closed cubes are and how they’re good in removing redundant aggregates from storage. I’ve wrote this for myself initially to get better insights on different aggregate situations and thought somebody might get interested as well. Go check it out, if you’re interested in how future olap engines will be working )))

Look how bad it is with all dense cubes, like (copy-paste these values):

  R2;spring
  R2;autumn
  R1;spring
  R1;autumn

and how good with more or less sparse ones

R2;spring;store1
R2;autumn;store2
R1;spring;store1
R1;autumn;store3