CREATE TABLE stocks(timestamp INT, price INT)

INSERT INTO stocks VALUES(1,15)
INSERT INTO stocks VALUES(2,19)
INSERT INTO stocks VALUES(3,16)
INSERT INTO stocks VALUES(4,17)
INSERT INTO stocks VALUES(5,15)
INSERT INTO stocks VALUES(6,13)
INSERT INTO stocks VALUES(7,5)
INSERT INTO stocks VALUES(8,8)
INSERT INTO stocks VALUES(9,7)
INSERT INTO stocks VALUES(10,13)
INSERT INTO stocks VALUES(11,11)
INSERT INTO stocks VALUES(12,14)
INSERT INTO stocks VALUES(13,10)
INSERT INTO stocks VALUES(14,5)
INSERT INTO stocks VALUES(15,2)
INSERT INTO stocks VALUES(16,5)

/*<k> "q1" </k>*/
-- SELECT max(price-min(timestamp)) FROM stocks

/*<k> "q2" </k>*/
SELECT max(price-mins(price)) FROM stocks

/*<k> "q3"</k>*/
SELECT price, timestamp FROM stocks where price - timestamp > 1 and not (price*timestamp<100)

/*<k> "q4"</k>*/
SELECT max(price-mins(price))
FROM stocks
     ASSUMING DESC timestamp