Dear,
I agree with all colleagues, One answer might look to be wrong to someone but it is also one of the solution somewhere. It all depends on the scenario as how you want to design your data load.
When you say addition and overwrite, You also need to look at what kind of design you have in place.
- How is your data source bringing delta, Is it bringing only after image, OR with Before and after image OR with additive image?
- Are you loading straight from data source to Cube?
- If you have DSO in between, what is the type of it (W/O OR Standard)?
For example if you your delta is bringing before and after than you don't have to be worried about, aggregation will automatically be corrected, since for each change delta brings in 2 records..saying this is one with -(minus) figure and other with positive figure.
How you want to show the value in reporting is all matters when you design do the design, pls. share your inputs so that we can input more on your requirement.
Thanks & Regards,
M