docs: private MaterializedRelation<ParameterizationFunction> buildDB(int dim, double[][] basis, DBIDs ids, Relation<ParameterizationFunction> relation) {
      ProxyDatabase proxy = new ProxyDatabase(ids);
      SimpleTypeInformation<ParameterizationFunction> type = new SimpleTypeInformation<>(ParameterizationFunction.class);
      WritableDataStore<ParameterizationFunction> prep = DataStoreUtil.makeStorage(ids, DataStoreFactory.HINT_HOT, ParameterizationFunction.class);
  
      // Project
      for(DBIDIter iter = ids.iter(); iter.valid(); iter.advance()) {
        prep.put(iter, project(basis, relation.get(iter)));
      }
  
      if(LOG.isDebugging()) {
        LOG.debugFine("db fuer dim " + (dim - 1) + ": " + ids.size());
      }
      MaterializedRelation<ParameterizationFunction> prel = new MaterializedRelation<>(type, ids, null, prep);
      proxy.addRelation(prel);
      return prel;
    }