[erlang-questions] dynamically add mnesia fragmented table node & composite key as index

[db]

Question 1:
I start an application that initializes several fragmented mnesia
nodes.  I have hard coded this into config file.  On later stage, if I
wanted to add another fragmented mnesia node, what is the solution?
Do I stop my application and then add a node in the config file?  What
approach I have to take, if I want to add node dynamically?

Question 2:
Can mnesia table index be made up of multiple attributes, as in
composite key?

thank you,
sleepless with erlang.