[racket] db connection pools

Hi all,

Does anything have to be done to safely shutdown a connection pool and 
close idle connections?   The documentation (6.0.1) says new connections 
are opened under the custodian that initialized the pool, but nothing 
directly is said about what happens when the custodian terminates, and 
there is no mention of a shutdown call. Can I assume that the idle 
connections are closed automatically?

Also, it is mentioned that an exception is thrown if 
connection-pool-lease fails, but not what exception.

Thanks,
George