Hi prashanth,
Actually there is no wrong at your dso, If you receive any issue from user like getting more/double key fig values then you need to check.
Normally DSO itself hold more granular data. as said above by experts, for same records you may have more combinations.
Copy the prod data in dev system and take abap expert help and Debug the DTP for first load and 2nd load(self load). you may find how the more records loaded.To know the exact reason you debug in dev environment.
Thanks