List the country name of the customers in the building marketing segment with an account balance greater than 80% of the average account balance of all customers.
country name refers to n_name; building marketing segment refers to c_mktsegment = 'BUILDING'; account balance greater than 80% of the average account balance of all customers refers to c_acctbal > MULTIPLY(AVG(c_acctbal), 0.8);
SELECT T2.n_name FROM customer AS T1 INNER JOIN nation AS T2 ON T1.c_nationkey = T2.n_nationkey INNER JOIN ( SELECT AVG(c_acctbal) * 0.8 AS avg_acctbal FROM customer ) AS T3 WHERE T1.c_acctbal > T3.avg_acctbal