what are the names of products whose availability equals to 1 ?
SELECT T2.product_name FROM view_product_availability AS T1 JOIN products_for_hire AS T2 ON T1.product_id   =   T2.product_id WHERE T1.available_yn   =   1
product names whose availability equals to 1 refers to selecting product_name from a product-related table where a column indicating availability (available_yn) equals 1; joining tables to match product IDs between a view that tracks availability and the main product list.