CREATE TABLE table_203_406 (id NUMBER, "entrant" CLOB, "constructor" CLOB, "chassis" CLOB, "engine" CLOB, "tyre" CLOB, "driver" CLOB, "rounds" CLOB)

what brand has been constructor the most ?
SELECT "constructor" FROM table_203_406 GROUP BY "constructor" ORDER BY COUNT(*) DESC LIMIT 1
SELECT "constructor" FROM "table_203_406" GROUP BY "constructor" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY