23 - Out of resources when opening file '/tmp/#sql_6eb_0.MAD' (Errcode: 24 "Too many open files")

select pd.products_description, p.products_id, p.products_image, p.products_price, p.products_tax_class_id, s.specials_new_products_price, specials_new_products_price, p.products_date_added from products p left join products_description pd on p.products_id = pd.products_id and pd.language_id = '4' left join specials s on p.products_id = s.products_id left join featured f on p.products_id = f.products_id where p.products_status = '1' and f.status = '1' order by rand() DESC limit 18