use MLDBM;
use Fcntl;
$dbm = tie %o, 'MLDBM', 'testmldbm', O_CREAT|O_RDWR, 0640 or die $!;

##</code><code>##

$tmp = $mldb{key};			# retrieve value
$tmp->{subkey}[3] = 'stuff';
$mldb{key} = $tmp;

##</code><code>##

use MLDBM;
use Fcntl;
$hash = tie %o, 'MLDBM', 'testmldbm', O_CREAT|O_RDWR, 0640 or die $!;
...
$tmp = $hash{$nameplace};
if ($male) {
   $tmp->{$person}[0]++;
} else {
   $tmp->{$person}[1]++;
}
$hash{$nameplace} = $tmp;