Oh, I see. That would be hard, actually. I also can't find any online databases and I doubt they exist. I think your best chance to find any records is to visit a museum of local lore in a city he lived. If he earned any medals — especially Saint George medal — or paricipated in some famous battle, your chances rise. But even then they are quite low. Most records probably were lost during the Revolution and Civil War, especially in Ukraine.