Support nested aggregates

SELECT sum(salary), row_number() OVER (ORDER BY depname), sum(
 sum(salary) FILTER (WHERE enroll_date > '2007-01-01')
) FILTER (WHERE depname <> 'sales') OVER (ORDER BY depname DESC) AS "filtered_sum",
 depname
FROM empsalary GROUP BY depname;

org.apache.spark.sql.AnalysisException
It is not allowed to use an aggregate function in the argument of another aggregate function. Please use the inner aggregate function in a sub-query.

SELECT sum(salary), row_number() OVER (ORDER BY depname), sum(
 sum(salary) FILTER (WHERE enroll_date > '2007-01-01')
) FILTER (WHERE depname <> 'sales') OVER (ORDER BY depname DESC) AS "filtered_sum",
 depname
FROM empsalary GROUP BY depname;
 sum | row_number | filtered_sum | depname 
-------+------------+--------------+-----------
 25100 | 1 | 22600 | develop
 7400 | 2 | 3500 | personnel
 14600 | 3 | | sales
(3 rows)