Cubes
Example:
CREATE CUBE salesCubeON salesDIMENSIONS prodid, custidGROUPS (prodid, custid) pc, (prodid) pMEASURES count(*), sum(price)
Each GROUP is held in a separate table:
PRODID COUNT(*) SUM(PRICE)
1000 14 $76.24 1001 34 $6.80
PRODID CUSTID COUNT(*) SUM(PRICE)
1000 10 5 $24.97 1000 40 9 $51.27