Listing 2: Materializing the Result Set in a Table
SET NOCOUNT ON;
USE tempdb;
GO
IF OBJECT_ID('dbo.MyGroupingSets', 'U') IS NOT NULL
  DROP TABLE dbo.MyGroupingSets;
GO

SELECT
  GROUPING_ID(
    custid, empid,
    YEAR(orderdate), MONTH(orderdate), DAY(orderdate) ) AS grp_id,
  custid, empid,
  YEAR(orderdate) AS orderyear,
  MONTH(orderdate) AS ordermonth,
  DAY(orderdate) AS orderday,
  SUM(qty) AS qty
INTO dbo.MyGroupingSets
FROM dbo.Orders
GROUP BY
  CUBE(custid, empid),
  ROLLUP(YEAR(orderdate), MONTH(orderdate), DAY(orderdate));

CREATE UNIQUE CLUSTERED INDEX idx_cl_grp_id_grp_attributes
  ON dbo.MyGroupingSets(grp_id, custid, empid, orderyear, ordermonth, orderday);