Ago - requires aggregation?

Question

Hi,
OBIEE 10.1.3.4
I have two columns in a fact table (simplified).
The two columns are identical in all material respects except that the first column has a sum aggregation on it, the second has no aggregation on it.
If I try to create a new logical column on the aggregated column using an AGO function to give previous period comparison on that column then everything works okay.
If I try to create a new logical column on the non-aggregated column using an AGO function to give previous period comparison on that column then I get an error (below).
[nQSError: 22038] Function AGO requires at least one measure attribute in its first argument.
The reason my second column is not aggregated is that the folder contains a mix of single month columns and full year columns - and this column falls into the latter category.
Can anyone tell me if there is a workaround so I can either use AGO on a non-aggregated column OR if there is a means to aggregate a YEAR column in such a way that it only SUMS on change of year.
i.e.
Column 1 = Budget in Month - so SUM(Month 1 to 12) yields a sensible result
Column 2 = Budget in Year - which for speed and convenience is shown at the same level as the column above - but which is essentially a precomputed value of sum(Month 1 to 12) as above. So Sum(Budget in Year Month 1 -12) would be nonsense.
thanks for your input,
Robert.
Edited by: Robert Angel on 27-May-2011 01:19 - to add version of software

Answer 1

Thanks for your input.
In a world where I was the only report writer I would agree, but this will be rolled out to end users, who admittedly will be trained, but I would prefer it if there was some means of either; -
a. Enforcing that certain measures must be present when certain columns are present - in my case if Annual Budget is used (with sum aggregate) then this only makes sense if Month / Financial Period is mandatory in combination.
Otherwise, as I have said
select year, sum(Annual Budget)
from  my_table
group by
         yearis a nonsense, but
select year, month, sum(Annual Budget)
from  my_table
group by
         year, monthIs okay - as the annual budget figure may change in the course of the year.