CREATE TABLE customers_policies (customer_id VARCHAR2)
CREATE TABLE customers (customer_name VARCHAR2, customer_id VARCHAR2)

What is the name of the customer who has the most policies listed?
SELECT t1.customer_name FROM customers AS t1 JOIN customers_policies AS t2 ON t1.customer_id = t2.customer_id GROUP BY t1.customer_name ORDER BY COUNT(*) DESC LIMIT 1
SELECT "t1"."customer_name" FROM "customers" "t1" JOIN "customers_policies" "t2" ON "t1"."customer_id" = "t2"."customer_id" GROUP BY "t1"."customer_name" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY