Saweens:
You have not specified what you are using, and you did not explain what you are going to do with the Duplicates.
Generaly, there are 3 steps to DETECT duplication.
1) Sort by the primary key.
2) Create a flag field.
2) Compare with the previous record, when duplicate, flag it ( example Flag field = 1)
Good Luck Kamal Khalil
Sr. Client Technical Analyst
kkhalil@Houston.ds.adp.com