Подсчёт строк с пустыми значениями

SELECT 
idq,
COUNT(npp),
AVG(dat_v - dat_p) AS avg_time,
MAX(dat_v - dat_p) AS max_time
FROM queue.stat 
WHERE dat_p BETWEEN '2020-10-01' AND '2020-10-31'
AND idq IN (1, 2, 3, 9, 10)
AND dat_p::TIME BETWEEN '8:00:00' AND '8:59:59'
GROUP BY idq;

SELECT 
idq,
COUNT(npp),
AVG(dat_v - dat_p) AS avg_time,
MAX(dat_v - dat_p) AS max_time
FROM queue.stat 
WHERE (dat_p IS NOT NULL) AND (dat_v IS NOT NULL) AND (dat_p BETWEEN '2020-10-01' AND '2020-10-31')
AND idq IN (1, 2, 3, 9, 10)
AND dat_p::TIME BETWEEN '8:00:00' AND '8:59:59'
GROUP BY idq;

SELECT 
idq,
COUNT(npp),
NULL AS avg_time,
NULL AS max_time
FROM queue.stat 
WHERE (dat_p IS NULL) OR (dat_v IS NULL)
AND idq IN (1, 2, 3, 9, 10)
GROUP BY idq;

SELECT idq, COUNT(npp), AVG(time_delta) AS avg_time, MAX(time_delta) AS max_time
   FROM
   (
       SELECT idq, npp, (dat_v - dat_p) AS time_delta FROM queue.stat WHERE idq IN (1, 2, 3, 9, 10)
   )
   WHERE dat_p BETWEEN '2020-10-01' AND '2020-10-31' AND dat_p::TIME BETWEEN '8:00:00' AND '8:59:59'
      GROUP BY idq

WITH 
grps(grp_id) AS (VALUES (1), (2), (3), (9), (10))
SELECT grp_id, COUNT(npp), avg(dat_v-dat_p) AS avg_time, MAX(dat_v-dat_p) AS max_time 
FROM grps
LEFT JOIN stat ON grps.grp_id=stat.idq
GROUP BY grp_id 
ORDER BY grp_id;

WHERE (dat_p IS NOT NULL) AND (dat_v IS NOT NULL) AND (dat_p BETWEEN '2020-10-01' AND '2020-10-31')

WITH 
grps(grp_id) AS (SELECT id FROM другая_таблица)

LEFT JOIN stat ON grps.grp_id=stat.idq AND dat_p BETWEEN '2020-10-01' AND '2020-10-31' AND dat_p::TIME BETWEEN '8:00:00' AND '8:59:59'