insert into some_table values (5, '*');
insert into some_table values (2, '*');
insert into some_table values (5, '*');
insert into some_table values (3, '*');
insert into some_table values (5, '*');
insert into some_table values (3, '*');
insert into some_table values (2, '*');
insert into some_table values (4, '#');
insert into some_table values (8, '#');
insert into some_table values (4, '#');
insert into some_table values (8, '#');
insert into some_table values (4, '#');
select dense_rank() over (partition by b order by a) dr,
rank() over (partition by b order by a) rk,
row_number() over (partition by b order by a) rn,
a,b
from some_table;