How Qualify operator work in teradata
The following statement displays each item in a sales table,
its total sales, and its rank within the top 100 selling items:
SELECT itemid, sumprice, RANK() OVER (ORDER BY sumprice DESC)
FROM (SELECT a1.item_id, SUM(a1.sale)
FROM sales AS a1
GROUP BY a1.itemID) AS t1 (item_id, sumprice)
QUALIFY RANK() OVER (ORDER BY sum_price DESC) <=100;