show status like '%window%';
Variable_name	Value
Feature_window_functions	0
create table t1 (a int, b int);
insert into t1 values (1, 10), (2, 20), (3, 30);
select a, b, rank() over (order by a) from t1;
a	b	rank() over (order by a)
1	10	1
2	20	2
3	30	3
show status like '%window%';
Variable_name	Value
Feature_window_functions	1
select a, b, rank() over (order by a), sum(a) over (order by a) from t1;
a	b	rank() over (order by a)	sum(a) over (order by a)
1	10	1	1
2	20	2	3
3	30	3	6
show status like '%window%';
Variable_name	Value
Feature_window_functions	2
select t_a.r1, t_b.r2
from (select a, b, rank() over (order by a) as r1 from t1) t_a,
(select a, b, row_number() over (order by a) as r2 from t1) t_b;
r1	r2
1	1
1	2
1	3
2	1
2	2
2	3
3	1
3	2
3	3
show status like '%window%';
Variable_name	Value
Feature_window_functions	4
drop table t1;