subtotal calculation in memory (not in DB) in Cognos 10.1.1

[kiran.timsina]

My reports have a lot of subtotals due to which the size of csv file has increased from 3 MB to 9 MB. This has made subtotal rendering very slow. Is there a way in Cognos 10.1.1 to calculate subtotals on the fly in memory instead of sending it to database?

If the report is Department vs. Sales Unit, the query would be something like
select dept, sales_unit
from .....

Now if I add subtotals on department and an overall total, the query would be something like
select dept, sales_unit, dept_subtotal, overall_total
from ...

Since dept_subtotal and overall_total are getting pulled as a column, they repeat across all rows. My actual report has 25 columns each column having 5 metrics and subtotals for 5 columns which has made my file size to become 3 times larger.