I have an invoice system with line items for parts and line items for labour.

I would like the sub total to be a number field instead of a calculation. But I can not get a result with the number field having a auto-enter calculation of sum (relation::amount).

I would like to avoid scripts for now. I would like the subtotal to be a number field so the DB remains fast and doesn't get bogged down over time and when performing reports.

Have you tried a summary field?

The summary would be the total of the "amount' field.

I think "rivet" is looking for something beyond this. The issue surrounds performance degredation with calculated values.

The auto-enter cannot work as it will evaluate on the first valid entry on a dependent field, from there on it will not re-evaluate.

About the only way to test the possible performance issue is to fill a dummy database suite with random values and see what happens. Try 10,000 records first then move upto 100,000 etc.

I have seen systems with > 100,000 records and quite a few calcs that have acceptable performance.

There has to be some level of compromise as the database is doing a lot of work, so all it is asking is a little time, other than this you must script it.

then scripting it is... thanks for the help