When should a social security number be used as a database primary key?

Question

Our DBA says that because the social security number (SSN) is unique, that we should use it as the primary key in a table.

While I do not agree with the DBA (and hav

Answer 1

Keys can only be determined from business rules. What matters is whether it makes sense in the context of your business requirements to enforce uniqueness of SSN or not. That is not a matter your DBA alone can decide on. It's something on which to consult the HR department or whoever else uses this data.

Assuming that your table will have at least one key (perhaps more than one) then I suggest that the DBA is in the best position to advise on the policy for primary keys. If the choice of a primary key is of any importance at all then the DBA ought to say so.