Multiple aggregations and group by in single query - mysql

Question

I have an SQL table with roughly the following structure:
Employee| date | department | Country | Designation
What I would like is to get results with the following structure:
count_emp_per_department | count_emp_per_country | count_emp_per_designation |
Currently I am using UNION ALL, that is constructing a query similar to that one:
SELECT emp_ID, NULL, count(1)
FROM employee
GROUP BY country
UNION ALL
SELECT NULL, emp_ID, count(1)
FROM film
GROUP BY designation
Is this the most effective way to perform multiple aggregations and return all of them in a single result set in Hive?
Kindly share if you new approach which can optimize/enhance performance.

Answer 1

Not sure whether its a real requirement.. as the output isnt that useful.. anyway
Here is the structure and query.
+-----------+------------+----------+
| col_name | data_type | comment |
+-----------+------------+----------+
| emp | int | |
| dt | date | |
| dept | string | |
| country | string | |
| desig | string | |
+-----------+------------+----------+
+--------+-------------+---------+------------+----------+
| t.emp | t.dt | t.dept | t.country | t.desig |
+--------+-------------+---------+------------+----------+
| 1 | 2020-02-02 | human | usa | hr |
| 2 | 2020-02-02 | dir | usa | hr |
| 3 | 2020-02-02 | dir | canada | it |
+--------+-------------+---------+------------+----------+
with q1 as (select dept,count(*) as deptcount from t group by dept),
q2 as (select country,count(*) as countrycount from t group by country),
q3 as (select desig,count(*) as desigcount from t group by desig)
select * from q1, q2, q3;
output will be like this..
+----------+---------------+-------------+------------------+-----------+----------------+
| q1.dept | q1.deptcount | q2.country | q2.countrycount | q3.desig | q3.desigcount |
+----------+---------------+-------------+------------------+-----------+----------------+
| dir | 2 | canada | 1 | hr | 2 |
| dir | 2 | usa | 2 | hr | 2 |
| dir | 2 | canada | 1 | it | 1 |
| dir | 2 | usa | 2 | it | 1 |
| human | 1 | canada | 1 | hr | 2 |
| human | 1 | usa | 2 | hr | 2 |
| human | 1 | canada | 1 | it | 1 |
| human | 1 | usa | 2 | it | 1 |
+----------+---------------+-------------+------------------+-----------+----------------+