Re: Storing "deleted" data

>b)You can try to declare a foreign key reference to one table AND another.

That doesn't help, though. Consider the following:

create table livePeople (

   personID int not null,
   ...
)

create table deadPeople (

   personID int not null,
   ...
)

create table personComment (

    personID int not null,
    commentID int not null
)

So what primary key does personComment.personID refer to? As far as I know, while it can refer to livePerson.personID AND

deadPerson.personID, it can't refer to livePerson.personID OR
deadPerson.personID.  Furthermore, there's no way to indicate that
livePerson.personID and deadPerson.personID have to be unique when