Basket pairs: what sells together

The recommendation team wants a quick "Frequently bought together" list before any machine learning. They look at pairs of different products that appear in the same non-cancelled order. Each pair must be counted once, regardless of order, so list the product with the smaller id first. Self joining order_items on order_id with a.product_id < b.product_id does exactly that.

Task: return product_a and product_b (product names, product_a has the smaller product id) and orders_together (number of orders containing both). Keep the top 8 pairs: sort by orders_together from high to low, then by product_a A to Z, then by product_b A to Z.