C# – Paging large amounts of Data in a Gridview

Ok, please bear with me as I can be a bit of a wood duck at times…

I have a gridview in asp.net that will be pulling back many thousand of records. This is all well and good apart from the performance aspect of things. I am binding my Gridview to a dataset and this pulls back every record in the query. I want to change this so that the gridview only pulls back the records that it is currently displaying and then when the user moves to the next page it goes and gets the next chuck of data etc.

Below is how I normally bind my gridviews and handle the paging and sorting, which works very well for me with small data amounts, but not so good for large data amounts. I use SubSonic as my DAL, which is cool. Can anyone point me in the right direction on how best to achieve paging as described above?

Thanks in advance…

public SortDirection SortDir
{
    get
    {
        if (ViewState["sortDirection"] == null)
        {
            ViewState["sortDirection"] = SortDirection.Ascending;
        } return (SortDirection)ViewState["sortDirection"];
    }
    set
    {
        ViewState["sortDirection"] = value;
    }
}

DataSet ds = new DataSet();
DataView dv = new DataView();

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        BindGrid();
        GridView1.DataSource = dv;
        GridView1.DataBind();
    }
}

private DataView BindGrid()
{
    ds = new Query(AnthemWeb.DAL.Item.Schema).ExecuteDataSet();

    if (ViewState["sortExpr"] != null)
    {
        dv = new DataView(ds.Tables[0]);
        dv.Sort = (string)ViewState["sortExpr"];
    }
    else
    {
        dv = ds.Tables[0].DefaultView;
    }

    return dv;
}

protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
    GridView1.PageIndex = e.NewPageIndex;
    GridView1.DataSource = BindGrid();
    GridView1.DataBind();
}

protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
    string stExp = e.SortExpression;
    string stDir = string.Empty;
    if (SortDir == SortDirection.Ascending)
    {
        SortDir = SortDirection.Descending;
        stDir = "DESC";
    }
    else
    {
        SortDir = SortDirection.Ascending;
        stDir = "ASC";
    }

    ViewState["sortExpr"] = e.SortExpression + " " + stDir;
    GridView1.DataSource = BindGrid();
    GridView1.DataBind();
}

protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
{
    int selectedRowIndex;
    selectedRowIndex = GridView1.SelectedIndex;
    GridViewRow row = GridView1.Rows[selectedRowIndex];
    string ID = row.Cells[0].Text;

    Response.Redirect("customer-details.aspx?ID=" + ID, false);
}