code: private void appendPersistentIndex(double[] vector) {
  		TupleOutput output = new TupleOutput();
  		for (int i = 0; i < vectorLength; i++) {
  			output.writeDouble(vector[i]);
  		}
  		DatabaseEntry data = new DatabaseEntry();
  		TupleBinding.outputToEntry(output, data);
  		DatabaseEntry key = new DatabaseEntry();
  		IntegerBinding.intToEntry(loadCounter, key);
  		iidToVectorDB.put(null, key, data);
  	}
docs: Appends the persistent index with the given vector.
  
  @param vector
  The vector