Limitations of the DataReader
Though the DataReader is faster and carries less overhead than binding to a DataSet , there are some limitations associated with using it. For instance, if you plan to use the paging features of Web controls, such as the DataGrid , you'll need to handle the data paging yourself. For more information, please see Hour 12, "Formatting ASP.NET List Controls." Additionally, it's not possible to sort , filter, or manipulate the data while using a DataReader , since it is read-only and forward-only.