What are the products available in the stores?
select product from product
What about the maximum page sizes supported by these products?
select product, max_page_size from product
Which products have a maximum page size A4?
select product from product where max_page_size = 'A4'
Which maximum page sizes are the maximum page size for more than 3 products?
select max_page_size from product group by max_page_size having count(*) > 3