>Hi,
>I used to see couples of thread that asking about how to delete the duplicated record.
>I just would like to know, why duplicated record will occured? Does PK or candicate key take care of the uniqueness, doesn't it?
>Or, any other case that will cause duplicated record?
>
>Sorry for my innocent.
>
>Thank you.

John,
I think those were related to human based duplications. For example you have list of addresses from 2 different sources and you want to merge.
Cetin