<<Assuming your testing on the production machine, simply copy the
database into another group (or account), and use file equations to
redirect testing. That is the least disruptive to developers (no changes
to programs between testing and production).

It is also probably the most dangerous, since unless you take care of
access restrictions, they might think they're on the test data, but are
actually on the live :)>>


That's why "another account" is a better answer than a new group in the
production account; you can put up the "write fence" on the production
account to make it impossible (well, at least really hard) to write into
the production databases from the development account, while still
allowing read access to update the development copy of the database.