On 2/18/25 12:56, dfgpostgres wrote:
Hi:
psql 15.3
I have a table with sets of observations, each set sharing an id.
I want to get the average of the max of each set.
id | val
-----------
1 5.0
1 4.3
1 3.8
2 4.8
2 6.0
2 2.9
3 4.1
3 4.4
3 8.0
So I want the avg of the max of the set where id=1 (5.0), where id=2
(6.0), where id=3 (8.0) ~= 6.33...
I tried this...
select
avg(x.maxsz)
from
dvm.dvm_events d,
(select cast(max(size_g) as int) as maxsz
from dvm.wa_du_profile_data
where dvm_id=d.dvm_id) x
where
d.project='foo' and
<more conditions on d>
It doesn't like that reference to "d.dvm_id) in that subquery.
create table wa_du_profile_data (id integer, val float);
insert into wa_du_profile_data values (1, 5.0),
(1, 4.3),
(1, 3.8),
(2, 4.8),
(2, 6.0),
(2, 2.9),
(3, 4.1),
(3, 4.4),
(3, 8.0);
with max_val as (select max(val) from wa_du_profile_data group by id)
select avg(max) from max_val;
6.333333333333333
--
Adrian Klaver
adrian.kla...@aklaver.com
