>When I do a query ... lets say, "SELECT MAX(COST) AS COST, INVNO FROM INVOICES" ... what do I know about the value of INVNO in the result set? ENGINEBEHAVIOR is 70. In all the testing I have done, it always SEEMS to return the value from the record containing the MAX() value. However, I don't KNOW any specifics about the code that performs the fetch, so I don't know whether this is a reliable observation or not.

You'll get INVNO from the last physical record in the table not from the record with MAX(COST).