CREATE TABLE airlines (alid NUMBER, name CLOB, iata CLOB, icao CLOB, callsign CLOB, country CLOB, active CLOB)
CREATE TABLE airports (apid NUMBER, name CLOB, city CLOB, country CLOB, x NUMBER, y NUMBER, elevation NUMBER, iata CLOB, icao CLOB)
CREATE TABLE routes (rid NUMBER, dst_apid NUMBER, dst_ap CLOB, src_apid NUMBER, src_ap CLOB, alid NUMBER, airline CLOB, codeshare CLOB)

What is the maximum elevation of all airports in the country of Iceland?
SELECT MAX(elevation) FROM airports WHERE country = 'Iceland'
SELECT MAX("elevation") FROM "airports" WHERE "country" = 'Iceland'