Hi Sreeyams
You have mentioned "after upgrade" in your heading but nothing was mentioned about it. Could you please give the details of the upgrade done.
Where is the problem now? Is it from DSO to cube?
In DSO, are there new records added every day?
Have you migrated your 3.5 flow to 7.x flow and is this problem happening after that?
Please give the above information and we will analyse and resolve further
Regards
Karthik