auto update that grid whene ever db table get affected

Hi ,
Well you can do it using Timer
Chech this example will guide you

<div>
     <asp:ScriptManager ID="ScriptManager1" runat="server">
     </asp:ScriptManager>
     <asp:Timer ID="Timer1" runat="server" ontick="Timer1_Tick" Interval="2000">
     </asp:Timer>
     <asp:UpdatePanel ID="UpdatePanel1" runat="server">
           <ContentTemplate>
               <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
           </ContentTemplate>
               <Triggers>

                   <asp:AsyncPostBackTrigger ControlID="Timer1" EventName="Tick" />

               </Triggers>
     </asp:UpdatePanel>
 </div>

protected void Timer1_Tick(object sender, EventArgs e)
{
     //Rebind your Gridview 
}

Best Regards
M.Mitwalli

1 - this is not possible. Your page cannot know when a table row is changed. All you can do is regular AJAX calls to CHECK if you have new data.

2 - This is not a new question. But, a grid view is a server concept, it does not exist on the client. You can't really reload it unless you use the hacky ASP.NET AJAX library to pretend that is what you are doing.

3 - No, it's not possible. The best you can do, is have all these pages calling timers to try to find out if there is data they need.