set allow_experimental_window_functions = 1;

-- just something basic

select number, count() over (partition by intDiv(number, 3) order by number) from numbers(10);

-- proper calculation across blocks

0	1
1	2
2	3
3	1
4	2
5	3
6	1
7	2
8	3
9	1
select number, max(number) over (partition by intDiv(number, 3) order by number desc) from numbers(10) settings max_block_size = 2;

-- not a window function

2	2
1	2
0	2
5	5
4	5
3	5
8	8
7	8
6	8
9	9
select number, abs(number) over (partition by toString(intDiv(number, 3))) from numbers(10); -- { serverError 63 }

-- no partition by

select number, avg(number) over (order by number) from numbers(10);

-- no order by

0	0
1	0.5
2	1
3	1.5
4	2
5	2.5
6	3
7	3.5
8	4
9	4.5
select number, quantileExact(number) over (partition by intDiv(number, 3)) from numbers(10);

-- can add an alias after window spec

0	0
1	1
2	1
3	3
4	4
5	4
6	6
7	7
8	7
9	9
select number, quantileExact(number) over (partition by intDiv(number, 3)) q from numbers(10);

-- can't reference it yet -- the window functions are calculated at the
-- last stage of select, after all other functions.

0	0
1	1
2	1
3	3
4	4
5	4
6	6
7	7
8	7
9	9
select q * 10, quantileExact(number) over (partition by intDiv(number, 3)) q from numbers(10); -- { serverError 47 }

-- must work in WHERE if you wrap it in a subquery

select * from (select count(*) over () c from numbers(3)) where c > 0;

-- should work in ORDER BY

1
2
3
select number, max(number) over (partition by intDiv(number, 3) order by number desc) m from numbers(10) order by m desc, number;

-- also works in ORDER BY if you wrap it in a subquery

9	9
6	8
7	8
8	8
3	5
4	5
5	5
0	2
1	2
2	2
select * from (select count(*) over () c from numbers(3)) order by c;

-- Example with window function only in ORDER BY. Here we make a rank of all
-- numbers sorted descending, and then sort by this rank descending, and must get
-- the ascending order.

1
2
3
select * from (select * from numbers(5) order by rand()) order by count() over (order by number desc) desc;

-- Aggregate functions as window function arguments. This query is semantically
-- the same as the above one, only we replace `number` with
-- `any(number) group by number` and so on.

0
1
2
3
4
select * from (select * from numbers(5) order by rand()) group by number order by sum(any(number) + 1) over (order by min(number) desc) desc;

-- different windows
-- an explain test would also be helpful, but it's too immature now and I don't
-- want to change reference all the time

0
1
2
3
4
select number, max(number) over (partition by intDiv(number, 3) order by number desc), count(number) over (partition by intDiv(number, 5) order by number) as m from numbers(31) order by number settings max_block_size = 2;

-- two functions over the same window
-- an explain test would also be helpful, but it's too immature now and I don't
-- want to change reference all the time

0	2	1
1	2	2
2	2	3
3	5	4
4	5	5
5	5	1
6	8	2
7	8	3
8	8	4
9	11	5
10	11	1
11	11	2
12	14	3
13	14	4
14	14	5
15	17	1
16	17	2
17	17	3
18	20	4
19	20	5
20	20	1
21	23	2
22	23	3
23	23	4
24	26	5
25	26	1
26	26	2
27	29	3
28	29	4
29	29	5
30	30	1
select number, max(number) over (partition by intDiv(number, 3) order by number desc), count(number) over (partition by intDiv(number, 3) order by number desc) as m from numbers(7) order by number settings max_block_size = 2;

-- check that we can work with constant columns

0	2	3
1	2	2
2	2	1
3	5	3
4	5	2
5	5	1
6	6	1
select median(x) over (partition by x) from (select 1 x);

-- an empty window definition is valid as well

1
select groupArray(number) over () from numbers(3);

-- This one tests we properly process the window  function arguments.
-- Seen errors like 'column `1` not found' from count(1).

[0]
[0,1]
[0,1,2]
select count(1) over (), max(number + 1) over () from numbers(3);

-- Should work in DISTINCT

1	3
select distinct sum(0) over () from numbers(2);

0
select distinct any(number) over () from numbers(2);

-- Various kinds of aliases are properly substituted into various parts of window
-- function definition.

0
with number + 1 as x select intDiv(number, 3) as y, sum(x + y) over (partition by y order by x) from numbers(7);

0	1
0	3
0	6
1	5
1	11
1	18
2	9