Enforce Referential Integrity not available.

I have a db that will eventually be split.
tblChild has PK ChildID and is a linked table
tblNote has FK ChildID (long).
Relationship window will allow me to drop PK on FK and declares
a one-to-many relationship. The Referential Integrity check
boxes are unavailable. If I create the relationship anyway
both ends of the line have just a small blob rather than
a 1, many or arrow.

I am guessing there's nothing I can do about it and that it is
happening because the table on the one side is external. Right?

What happens when I split and the tables are in different
back ends? Am I in trouble?

--
Len
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