CREATE TABLE country (country_id DECIMAL, name TEXT, population DECIMAL, area DECIMAL, languages TEXT)
CREATE TABLE roller_coaster (roller_coaster_id DECIMAL, name TEXT, park TEXT, country_id DECIMAL, length DECIMAL, height DECIMAL, speed TEXT, opened TEXT, status TEXT)

Please show the most common status of roller coasters.
SELECT status FROM roller_coaster GROUP BY status ORDER BY COUNT(*) DESC LIMIT 1
SELECT "status" FROM "roller_coaster" GROUP BY "status" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1