>In addition to Craig's comment, there are probably millions of other duplicate SSN's: NULL, i.e. the one belonging to people who don't have a SSN. :)
>
>I don't know why you were asking about Canadian unique IDs, but you know what we're going to say: Don't use real data for primary keys. :)
i know and i'm not -- our company likes to keep some semi-unique id number and is interested what canada uses.