From: | Tomasz Myrta <jasiek(at)klaster(dot)net> |
---|---|
To: | pgsql-sql(at)postgresql(dot)org |
Subject: | sub-select with aggregate |
Date: | 2002-10-23 10:07:09 |
Message-ID: | 3DB674CD.50404@klaster.net |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-sql |
Hi
I want to perform query looking like this:
select
user_id,
a/sum_a as percent_a,
b/sum_b as percent_b
from
users join
(select
group_id,
sum(a) as sum_a,
sum(b) as sum_b
from users group by group_id) X using (group_id)
where group_id=3;
This query works, but very slow. Subquery with aggregate is performed
for all table rows instead of group_id=3.
I wish I could write it like this, but it doesn't work at all:
select
user_id,
a/sum_a as percent_a,
b/sum_b as percent_b
from
users U,
(select
sum(a) as sum_a,
sum(b) as sum_b
from users where group_id=U.group_id) X
where group_id=3;
I don't want to make it as single query with "group by", because it has
a lot of fields and "group by" would be very long.
Regards,
Tomasz Myrta
From | Date | Subject | |
---|---|---|---|
Next Message | jasiek | 2002-10-23 10:14:26 | Re: odbc drivers |
Previous Message | Tomasz Myrta | 2002-10-23 08:44:45 | Re: sub-select with aggregate |