Question: What are the names of the products that have the characteristic name "fast"?
SQL: SELECT product_name FROM products AS t1 JOIN product_characteristics AS t2 ON t1.product_id   =   t2.product_id JOIN CHARACTERISTICS AS t3 ON t2.characteristic_id   =   t3.characteristic_id JOIN ref_colors AS t4 ON t1.color_code   =   t4.color_code WHERE  t3.characteristic_name   =   "fast"