my @arr = @$db;
for (0..3) {
  $id = $arr[$_]->{id};
  $dbserv = $arr[$_]->{dbserv};
}

## oder
# C-like
for (my @arr = @$db, my $i=0; $i<=3; $i++) {
  $id = $arr[$_]->{id};
  $dbserv = $arr[$_]->{dbserv};
}

## oder
# als Array-Splice
for (@$db[0..3]) {
  $id = $_->{id};
  $dbserv = $_->{dbserv};
}