哪个数据集创建技术更快?

哪种技术更快?

1)

DbDataAdapter dataAdapter = _factory.CreateDataAdapter();
dataAdapter.SelectCommand = _command;

dataSet = new DataSet();

dataAdapter.Fill(dataSet);

2)

DataTable dt = new DataTable();

IDataReader iDataReader= _command.ExecuteReader();

dt.Load(iDataReader);

iDataReader.Close();