使用MD5 Hash作为主键与使用int标识作为SQL Server主键的优缺点

I have an application to deal with a file and fragment it to multiple segments, then save the result into sql server database. There are many duplicated file (maybe with different file path), so first I go through all these files and compute the Md5 hash for each file, and mark duplicated file by using the [Duplicated] column.I have an application to deal with a file and f