Question

Is it possible to apply multiple window functions to the same partition? (Correct me if I’m not using the right vocabulary)

For example you can do

SELECT name, first_value() over (partition by name order by date) from table1

But is there a way to do something like:

SELECT name, (first_value() as f, last_value() as l (partition by name order by date)) from table1

Where we are applying two functions onto the same window?

Reference:
http://postgresql.ro/docs/8.4/static/tutorial-window.html

Answer 1

Can you not just use the window per selection

Something like

SELECT  name, 
        first_value() OVER (partition by name order by date) as f, 
        last_value() OVER (partition by name order by date) as l 
from table1

Also from your reference you can do it like this

SELECT sum(salary) OVER w, avg(salary) OVER w
FROM empsalary
WINDOW w AS (PARTITION BY depname ORDER BY salary DESC)