Data Mart load does not support Delta load?

Question

For data mart load, we create an InfoPackage for Delta load, under data selection tab, for the InfoObj. 0FISCPER, we pick OLAP variable 0FPER [Current Fiscal Year/Period (SAP Exit)], save this InfoPackage, but when get in again, find under Data Selection tab, on the row 0FISCPER, the From Value column becomes 001/2005 and To Value column becomes 011/2005 and the whole Data Selection tab screen becomes non-editable! 
The correct behavior should be that after saving the InfoPackage on this row 0FISCPER, From Value/To Value columns are blank and just the Type column value is 7 and after saving the infopackage and get back in, the Data Selection tab screen is editable.
But if we select Full update mode, then switch back to the Data Selection tab, then the behavior is right. 
We wonder if SAP doesn't support Delta load for Data Mart load, why under the Update tab, the Delta load radio button shows up after we conducted an initial load?  It doesn't make any sense for SAP!

Answer 1

Dear,
as alredy suggested, you cannot do different selection criteria on your delta, since you automatically have to load on the basis of initial selection...and, if you think about it, this is logic: you cannot initialize a flow for certain conditions and then decide to upload in delta other (different) records...
Hope now is clearer...
Bye,
Roberto
clearly, if you perform a full (like a 'repair' full, from a functional point of view), this problem doesn't exist (data is taken from active table and not from change log one!)