sub send_mail {
   my $msg = shift;
   # send mail here...

   warn $msg;
   exit;
}

##</code><code>##

my $dbh = DBI->connect('DBI:Oracle:host=**,sid=***', 'usrname', 'passwd', { RaiseError => 1, AutoCommit => 0 } ) 
   || send_mail "Database connection not made:$DBI::errstr";