How can I write a window function using something like row_number to increment only on discrete values? Say I want to do something like:

select 
     my_date,
     row_number() over(partition by my_date order by my_date asc)
from
     my_table


I want the row numbers to come out as:

2018-10-01,1
2018-10-01,1
2018-10-02,2
2018-10-03,3


Not quite sure how to do this. With the current window function, it does:

2018-10-01,1
2018-10-01,2
2018-10-02,1
2018-10-03,1
You want dense_rank() instead of row_number()

select my_date,
       dense_rank() over(order by my_date asc)
from my_table