my $entries =
    eval {
        my $entries = 0;
        my $sth = $dbh->prepare ($sql); #2

        while (my ($name, $age) = each %people) { #3
            ++$entries if $sth->execute ($name, $age); #4
        }

        $dbh->commit (); #5
        return $entries;
    } or do {
        my $err = $@;

        eval {$dbh->rollback ()} or $err .= "\n   Rollback processing failed!";
        die $err;
    };