What code action updates a sum query

[dbaldwin]

I have a form based on a query that sums the values in a field. When I was writing the code to store the sumed value into a memory variable, I didn't know if simply writing something like memvar = frm!control would cause the underlying query to update and provide the most up to date sum. I chose to open the form DoCmd.OpenForm "frm" before I stored the value to the memory variable. It worked fine but, for future reference, was I just wasting my time with an unnecessary step?