show the exist nodes which are not unique of a specific cck field

show the exist nodes which are not unique of a specific cck field

as you know , losts of people use feedapi to collect their nodes , it's not a good idea to set a unique field before aggregate , how do you say?

but i after a lot of nodes had beed collected or aggregated by feedapi , administrators of the site will of course have to think that if some of his nodes contains the same content of a specific field , so he would like to delete the dumps

as in my site :
i use feedapi to collect videos or TVs like "mms://ipv6.XXXX.com/cctv1" or "rstp://video.xxxx.com/movie1"
but as you can imagine , while tv links will sometimes have a repeat value . in this situlation , i would like to use your module to remove the repeated one .

is it possible to accomplish this by your module or snippets or API , or other ways like mysql?