Hi Ashish,
As suggested by mates, no standard dso. you can with custome defined one.
Write optimized dso will give the data once its loaded to DSO without activation step. which reduce one step comapre to standard dso.
if you want go with standard dso, then with help of source team you may find primary keys of this data sources(from base tables and thru fucntional team.)
You can check fields of data source:
http://help.sap.com/saphelp_bw31/helpdata/en/87/c299397f3d11d5b3430050dadf08a4/content.htm
Thanks