What is the characteristic name used by most number of the products?
create table products (product_id varchar, PRIMARY KEY (product_id)); create table characteristics (characteristic_name varchar, characteristic_id varchar, PRIMARY KEY (characteristic_name)); create table product_characteristics (product_id varchar, characteristic_id varchar, PRIMARY KEY (product_id))
select 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 group by t3.characteristic_name order by count(*) desc limit 1