How many distinct characteristic names does the product "basil" have?
SELECT count ( DISTINCT t3.characteristic_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 WHERE t1.product_name   =   "basil"
distinct characteristic names = COUNT(DISTINCT characteristic_name); product 'basil' refers to WHERE product_name = 'basil';