>No; the concept of Rushmore is that the data file itself isn't read until the result set is needed; it first attempts to use the .CDX file to service elements of the query to restrict the record set needed to solve the Select statement, and only then will pull data from the file to resolve any query elements that cannot be serviced by existing indexes. It builds temporary indexes as needed, and these do not persist beyond the query, so that if the elements of a query can be serviced from existing index tags, only the .CDX file segments and the result set of the select cross the wire.

I think there's a very simple way to test one single query: run it from one workstation with Set Optimize ON, and from another machine with Set Optimize OFF. then reboot both machines and change roles and the order of runs (just to minimize the influence of caching). Keep measuring the traffic. See the effect.