This query:
SELECT min( "x" ) as "From",
max( "x" ) as "To",
sum("quantity")
FROM (
SELECT t.*,
ntile( 4 ) over (order by "x" ) as group_no
FROM table1 t)GROUP BY
group_no
ORDER BY 1;
with this data
x quantity
1 9
2 43
3 21
4 26
6 14
7 38
8 14
9 20
10 20
11 30
12 32
13 37
14 27
15 22
16 34
17 9
18 4
19 24
20 42
21 21
22 16
23 34
24 9
25 49
26 21
27 20
28 28
29 6
30 3
Has this result:
1 6 113
7 11 122
12 16 152
17 21 100
22 26 129
27 30 57
Is there any other SQL possibility that sum(quantity) is distributed more equally?
I know there are a lot of algorithms but I am pretty sure there must be smart SQL (analytic function) solution e.g..