protected System.Web.UI.WebControls.DataGrid dgDados;
protected System.Web.UI.WebControls.Label lblMsg;

private void Page_Load( object sender, System.EventArgs e)
{
    if ( !Page.IsPostBack )
      dgDados.DataSource = GetData();
      dgDados.DataBind();
}

private DataTable GetData()
{
    if ( Cache["teste"] != null )
    {
       lblMsg.Text = "Informando dados do CACHE";
       return (DataTable)Cache["teste"];
    }
    else
    {
       lblMsg.Text = "Informando dados do BANCO DE DADOS";

       SqlConnection conn = new SqlConnection();
       conn.ConnectionString = "Server=Localhost;Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=pubs;";

       SqlDataAdapter da = new SqlDataAdapter("select * from authors",conn);
       DataTable dt = new DataTable("authors");

       da.Fill(dt);

       Cache.Insert("teste",dt, new CacheDependency("E:\\Projetos Visual Studio.NET\\SQLCache\\cache\\" + "authors.txt"));

       return dt;
     }
}

class LimpaCache
{
     public static string  ArquivoTxt = @"E:\Projetos Visual Studio.NET\SQLCache\cache\";

     [STAThread]
     static void Main( string [] args)
     {
          try
          {

          string _table = args[0].ToString();
          Random _r = new Random( unchecked ( ( int ) DateTime.Now.Ticks ) );
          string _value = _r.Next().ToString();
          StreamWriter _SWriter = new StreamWriter(File.Open(ArquivotTxt + _table + ".txt",FileMode.Open,FileAccess.Write));

          _SWriter.Write( _value );

          _SWriter.Close();

          }
          catch ( Exception )
          {
               Console.WriteLine("Argumento nao especificado");
               Console.ReadLine();
          }
     }
}

Leituras imperdíveis para quem está começando: