Why Base a Relationship on a Query

[Harold]

I am trying to understand why this might be done.

Because it does not honor Referential Integrity is there some advantage to
define this in the relationship window.

Is there some performance gain?

 

[KARL DEWEY]

You might have two tables you want to relate but the data was formated
differently so using a calculated field you could then relate them.

Example --
Table_A Table_B
B123 123
C439 439

Fullname FName LName
Smith, Joe Joe Smith

 

[Harold]

I can do that in the Query Window. I still don't understand the advantage of
doing that in the Relationship Window, especially if Referential Integrity in
not honored.

I must be missing something.

 

[John W. Vinson]

I can do that in the Query Window. I still don't understand the advantage of
doing that in the Relationship Window, especially if Referential Integrity in
not honored.

AFAIK the only advantage of such a relationship is that it serves as a default
if you create a query using the objects being related. This can save a couple
of seconds. The performance depends on the indexes on the joined fields, and
the relationship window won't do anything with the indexes unless it's a
relationship with integrity enforced.