ข้อมูลใน DATABASE SQL SERVER 2005 เยอะมากๆ มันขึ้น OutOfMemoryException มีวิธีแก้ปัญหาหรือเปล่าครับ ภาษา C# ครับ

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace Search_HNIPD_Listview
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        SqlConnection Conn;
        StringBuilder sb = new StringBuilder();
        DataSet ds = new DataSet();
        string strConn;

        private void showdata()
        {
            sb.Remove(0, sb.Length);
            sb.Append("SELECT HNIPD_INVOICE_HEADER.AN, HNIPD_INVOICE_ITEM.HNActivityCode ");
            sb.Append("FROM HNIPD_INVOICE_HEADER, HNIPD_INVOICE_ITEM ");
            sb.Append("Where HNIPD_INVOICE_HEADER.AN=HNIPD_INVOICE_ITEM.AN");
            
            string EmployeesSQL = sb.ToString();
            SqlDataAdapter da = new SqlDataAdapter(EmployeesSQL, Conn);
            DataTable tb = new DataTable();
            DataSet ds = new DataSet();
            da.Fill(ds, "Received");
            myDgv.DataSource = ds.Tables["Received"];
        }


        private void Form1_Load(object sender, EventArgs e)
        {
            strConn = "Data Source=SSB-DB;Initial Catalog=TRAIN_DNHOSPITAL;Integrated Security=True";
            Conn = new SqlConnection();
            if (Conn.State == ConnectionState.Open)
            {
                Conn.Close();
            }
            Conn.ConnectionString = strConn;
            Conn.Open();

             }

        private void btnSearch_Click(object sender, EventArgs e)
        {
            showdata();
        }
    }
}