CUBE for All Combinations

`CUBE` goes further than `ROLLUP`: it produces every possible combination of the listed columns.

SELECT region, product, SUM(amount) AS total_amount
FROM revenue
GROUP BY CUBE (region, product)

`CUBE(region, product)` expands to four grouping sets:

(region, product) — detail level (region) — per region (product) — per product () — grand total

With n columns, `CUBE` produces 2^n grouping sets. That makes it ideal for full cross-tabulation reports where you want totals along every dimension.

`CUBE` is equivalent to writing out a `GROUPING SETS` clause that lists every subset of the columns. The result is the same, but `CUBE` is more concise.