tramp does not see directory changes

[Hans Halvorson]

I have noted that if Tramp is used to visit a file in a remote
directory, and if that remote directory is altered (e.g. a new file is
created), then Tramp is not aware of the changed state of the
directory.

For example, suppose I visit file "foo", and then I create (outside of
emacs) another file "bar" (in the same remote directory as "foo").  If
I then attempt to use autocompletion, Tramp/Emacs will not
autocomplete the filename "bar" -- it seems not to know of its
existence.

I suppose that Tramp caches the directory contents (for speed), and
that it would slow things down to check for new files.  Was that the
rationale behind the current setup?

Thanks,
Hans