CREATE TABLE table_204_312 (id NUMBER, "stage" CLOB, "date" CLOB, "route" CLOB, "terrain" CLOB, "length" CLOB, "winner" CLOB)

which type of terrain is listed the most ?
SELECT "terrain" FROM table_204_312 GROUP BY "terrain" ORDER BY COUNT(*) DESC LIMIT 1
SELECT "terrain" FROM "table_204_312" GROUP BY "terrain" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY