Sam Mason wrote:
> Do you really want the SUM of num1 and num2, because that makes it more
> fiddly and would be where having MAX accept a record/tuple would be
> best. If you don't, maybe something like:
>
> SELECT DISTINCT ON (date_trunc('day', mydate))
> date_trunc('day', mydate), num, num1+num2
> FROM mytab
> ORDER BY date_trunc('day', mydate), num DESC;
>
Unfortunately, I need:
- the SUM of some values, grouped per day
- the MAX of some other value, grouped per day
- the timestamp where the MAX above happened (per day, of course)
The "num" columns are events, and sometimes I need to know not only the
amount of a certain event per day, but also WHEN the MAX of some event
happened...
I guess I have to use a Composite Type (something like "numeric,
timestamp") + user defined aggregate?