CREATE TABLE table_203_166 (id DECIMAL, "pos" TEXT, "no" DECIMAL, "rider" TEXT, "manufacturer" TEXT, "laps" DECIMAL, "time" TEXT, "grid" DECIMAL, "points" DECIMAL)

which rider completed all 21 laps of the 2008 malaysian motorcycle grand prixwith the longest time ?
SELECT "rider" FROM table_203_166 WHERE "laps" = 21 ORDER BY "pos" DESC LIMIT 1
SELECT "rider" FROM "table_203_166" WHERE "laps" = 21 ORDER BY "pos" DESC NULLS LAST LIMIT 1