Hi Sylvia.

>I turned on RI, and it objects, "Cascade updates that are based on an expression-based index key may not behave as expected. The system has identified expression based keys in the following relationships."
>
> wellunit + wellinsp

It's best to avoid using compound (ie. more than one field) keys in joins between tables. Say WELLUNIT is the foreign key field to the other table. Create an index on it *and* create one on WELLUNIT + WELLINSP as your candidate key. Then, use the WELLUNIT tag for RI.

>Would SDT be useful by making a calculated field of this expression to fool RI?

No, because calculated fields don't actually exist; they're just an expression pre-defined in the meta data tables that you can use in various places by specifically asking for the expression property.

Doug