SELECT * FROM (SELECT 1 AS k FROM numbers_mt(1)) t1 LEFT JOIN (SELECT 1 AS k FROM numbers_mt(10000000000) WHERE number = 1) t2 USING k SELECT * FROM (SELECT 1 AS k FROM numbers_mt(1)) t1 LEFT JOIN (SELECT 1 AS k FROM numbers_mt(10000000000) GROUP BY k) t2 USING k SELECT * FROM (SELECT 1 AS k FROM numbers_mt(1)) t1 LEFT JOIN (SELECT 1 AS k FROM numbers_mt(10000000000) WHERE number = 1) t2 ON t1.k = t2.k