// Store the properties into a vector
   vec_str_int_type propvec; propvec.reserve(num_keys);

   std::string key, value;
   int64_t *bigendian_num = reinterpret_cast<int64_t*>(value.data());
   std::unique_ptr<tkrzw::DBM::Iterator> iter = dbm.MakeIterator();

   iter->First();
   while (iter->Get(&key, &value) == tkrzw::Status::SUCCESS) {
      propvec.emplace_back(key, bswap_64(*bigendian_num));
      iter->Next();
   }
   dbm.Close();