Oracle Sql Group Avarage за месяц

Question

У меня есть одна таблица, например

ID    REFGROUP     YEAR   MONTH   VALUE
---     -----    ------  -----   -----
1       1000       2018    1       10
2       1000       2018    2       8 
3       1000       2018    3       12
4       2000       2018    1       6
5       2000       2018    2       8
6       2000       2018    3       1

Я хочу получать средний месяц за месяцем по группе и году

ID    REFGROUP     YEAR   MONTH   VALUE
---    -----    ------  -----   -----
1       1000       2018    1       10
2       1000       2018    2       9 
3       1000       2018    3       10
4       2000       2018    1       6
5       2000       2018    2       7
6       2000       2018    3       5

Результат будет выше.За второй месяц получите среднее значение за первые два месяца.В течение третьего месяца Iw будет получать среднюю из первой трехмесячной группы по группам и годам.

Я пробовал объединение для каждого месяца, но.Это делает медленную производительность.Я сделаю оба 12 месяца для каждого года так.Как можно написать SQL-запрос, чтобы сделать быстрее, чем я написал.Мой занимает 8 минут, что слишком много

select 1 AS AMONTHH, REFGROUP,AYEAR, AVG(TOTAL) from BMS.FNC_W_PAYROL WHERE AMONTH<=1 GROUP BY REFGROUP,AYEAR
UNION
select 2 AS AMONTHH, REFGROUP,AYEAR, AVG(TOTAL) from BMS.FNC_W_PAYROL WHERE AMONTH<=2 GROUP BY REFGROUP,AYEAR
UNION
select 3 AS AMONTHH, REFGROUP,AYEAR, AVG(TOTAL) from BMS.FNC_W_PAYROL WHERE AMONTH<=3 GROUP BY REFGROUP,AYEAR
UNION
select 4 AS AMONTHH, REFGROUP,AYEAR, AVG(TOTAL) from BMS.FNC_W_PAYROL WHERE AMONTH<=4 GROUP BY REFGROUP,AYEAR
UNION
select 5 AS AMONTHH, REFGROUP,AYEAR, AVG(TOTAL) from BMS.FNC_W_PAYROL WHERE AMONTH<=5 GROUP BY REFGROUP,AYEAR
UNION
select 6 AS AMONTHH, REFGROUP,AYEAR, AVG(TOTAL) from BMS.FNC_W_PAYROL WHERE AMONTH<=6 GROUP BY REFGROUP,AYEAR
UNION
select 7 AS AMONTHH, REFGROUP,AYEAR, AVG(TOTAL) from BMS.FNC_W_PAYROL WHERE AMONTH<=7 GROUP BY REFGROUP,AYEAR
UNION
select 8 AS AMONTHH, REFGROUP,AYEAR, AVG(TOTAL) from BMS.FNC_W_PAYROL WHERE AMONTH<=8 GROUP BY REFGROUP,AYEAR
UNION
select 9 AS AMONTHH, REFGROUP,AYEAR, AVG(TOTAL) from BMS.FNC_W_PAYROL WHERE AMONTH<=9 GROUP BY REFGROUP,AYEAR
UNION
select 10 AS AMONTHH, REFGROUP,AYEAR, AVG(TOTAL) from BMS.FNC_W_PAYROL WHERE AMONTH<=10 GROUP BY REFGROUP,AYEAR
UNION
select 11 AS AMONTHH, REFGROUP,AYEAR, AVG(TOTAL) from BMS.FNC_W_PAYROL WHERE AMONTH<=11 GROUP BY REFGROUP,AYEAR
UNION
select 12 AS AMONTHH, REFGROUP,AYEAR, AVG(TOTAL) from BMS.FNC_W_PAYROL WHERE AMONTH<=12 GROUP BY REFGROUP,AYEAR

Answer 1

Мы можем использовать аналитические функции здесь:

SELECT
    ID, REFGROUP, YEAR, MONTH,
    AVG(VALUE) OVER (PARTITION BY REFGROUP, YEAR ORDER BY MONTH) AVG_VALUE
FROM yourTable
ORDER BY
    REFGROUP, YEAR, MONTH;

Демо