my %features;
my %plans;
my %feat_plan_val;
while ( my ( $feat_id, $feat_name,
             $plan_id, $plan_name,
             $val ) = $sth->fetchrow_array() )
{
    $features{$feat_id} = $feature_name;
    $plans{$plan_id} = $plan_name;
    $feat_plan_val{$feat_id}{$plan_id} = $val;
}

# later...

my @plan_ids = sort keys %plans;
print join( "\t", 'Features', @plans{@plan_ids} ), "\n";
foreach my $feat_id ( sort keys %features )
{
    my @vals = ( $features{$feat_id} );
    foreach my $plan_id ( @plan_ids )
    {
        my $val = $feat_plan_val{$feat_id}{$plan_id};
        push @vals, ( defined $val ? $val : '-' );
    }
    print join( "\t", @vals ), "\n";
}