CREATE TABLE player (player_id NUMBER, name CLOB, position CLOB, club_id NUMBER, apps NUMBER, tries NUMBER, goals CLOB, points NUMBER)
CREATE TABLE competition_result (competition_id NUMBER, club_id_1 NUMBER, club_id_2 NUMBER, score CLOB)
CREATE TABLE competition (competition_id NUMBER, year NUMBER, competition_type CLOB, country CLOB)
CREATE TABLE club (club_id NUMBER, name CLOB, region CLOB, start_year CLOB)
CREATE TABLE club_rank (rank NUMBER, club_id NUMBER, gold NUMBER, silver NUMBER, bronze NUMBER, total NUMBER)

What is the most common competition type?
SELECT competition_type FROM competition GROUP BY competition_type ORDER BY COUNT(*) DESC LIMIT 1
SELECT "competition_type" FROM "competition" GROUP BY "competition_type" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY