use MLDBM qw(DB_File Storable);
# ... stuff ....
foreach $gid (@group_ids) {
	my %temp_hash;
	unlink "$DBFilePath/$$.$gid" if -e "$DBFilePath/$$.$gid";
	tie %temp_hash, 'MLDBM', "$DBFilePath/$$.$gid", O_RDWR|O_CREAT, 0640
			or die "Can't tie temp_array to $DBFilePath/$$.$gid: $!";
	$data[$gid] = \%temp_hash;

	foreach $sample_id (@{$groups[$gid]}) {
		foreach $element_num ( 0 .. $element_count ) {
			$element = [];
			# ... do a bunch of stuff here ...
			$data[$gid]->{$sample_id}->[$element_num] = $element;
		}
	}
}