Why does Discoverer put my custom function into GROUP BY

Question

To make things clear with simple example:
I have 10 id's from people (people.id) and sum function on their salary [sum(people.salary)] during a period of time that i set in my parameters.
The sql looks something like this:
SELECT PEOPLE.ID
,SUM(PEOPLE.SALARY)
FROM FRS_PEOPLE
WHERE [MY CONDITIONS]
GROUP BY PEOPLE.ID
I registered a function that uses people.id, and some other parameters to calculate something for each people.id!
I made a calculation:
MY_FUNCTION(people.id,'xxx','yyy')
,so my sql looks like this now:
SELECT PEOPLE.ID
,SUM(PEOPLE.SALARY)
,MY_FUNCTION(people.id,':xxx',':yyy')
FROM FRS_PEOPLE
WHERE [MY CONDITIONS]
GROUP BY PEOPLE.ID,MY_FUNCTION(people.id,':xxx',':yyy')
It runs but never finishes....?!
When i run my sql in sqlplus i do not put my function into group by, but discoverer does so, despite it already has people.id item in GROUP BY!
And if i put instead of people.id an actual id it works correctly and does not put my function into group by!
The sql i am looking for and works correctly is:
SELECT PEOPLE.ID
,SUM(PEOPLE.SALARY)
,MY_FUNCTION(people.id,'xxx','yyy')
FROM FRS_PEOPLE
WHERE [MY CONDITIONS]
GROUP BY PEOPLE.ID
Please someone help!
My select clause is much more complicated, with many outer joins so i made the above up just to explain to you what my problem is!
I hope i made my self clear!
Help would be very appreciated.

Answer 1

Hi,
I think there is a problem with your function. That fact that the report completes when an actual id is used must not when a people.id is used suggests that it works when the function is called once with an actual id but not when it is called many times with a people.id.
If the function is doing complex lookups and calculations to obtain a salary for each people.id then often this type of report will run quicker with the salary calculation is brought into the report SQL using joins etc.
Tracing the Discoverer session running the report will show you all the SQL processed by the database and the execution plans used. It will show you how often the function is being called and what SQL is being run by the function.
Rod West