> Also, if I have a bunch of other apps running on the same computer,
> and there's no way to control how much memory the database uses, what
> prevents the firebird from hogging all the memory, slowing down all
> other apps running on the machine?

Stop-stop-stop. Firebird is not a wild animal that is not under control.
It uses as much memory as you have configured, the rest is done then in
the "swap" files in the temp directory. Only that the -Xmx parameter
does not work for Firebird, you have to use other configuration
possibilities.

Roman