adding attributes to a database handle

Two questions:

1. Is it possible to add/store "user defined" attributes in a database handle.

I'd like to do something like this:

my $dbh = DBI->connect(...);

$dbh->{important_info} = ...;

...

print "the important info was: ", $dbh->{important_info}, "\n";

2. Is there anything preventing the sub-classing of database handles
(i.e. reblessing into a sub-class after creation)?