问个关于SqlDataAdapter的Update有关问题

问个关于SqlDataAdapter的Update问题

C# code

为什么下面的updateThreadRun()函数的tAdapter.Update(tds.Tables[0])动作那么慢，我只是修改了1000行记录，2个打印时间居然相差1秒，是不是我的tAdapter某些设置不正确?private void button2_Click(object sender, EventArgs e)        {            button2.Enabled = false;            button3.Enabled = true;            tSelectCommand = sc.CreateCommand();            tUpdateCommand = sc.CreateCommand();            tAdapter = new SqlDataAdapter(tSelectCommand);            tAdapter.UpdateCommand = tUpdateCommand;            tSelectCommand.CommandText = "SELECT * FROM NowXcData";            tUpdateCommand.CommandText = "UPDATE NowXcData SET TimeST = @TimeST WHERE CollectNodeId = @CollectNodeId";            tUpdateCommand.Parameters.Clear();            tUpdateCommand.Parameters.Add("@TimeST", SqlDbType.DateTime, 8, "TimeST");            tUpdateCommand.Parameters.Add("@CollectNodeId", SqlDbType.Int, 4, "CollectNodeId");            tAdapter.Fill(tds);            _tUpdate = new Thread(new ThreadStart(updateThreadRun));            _tUpdate.Start();        }        private void updateThreadRun()        {            while(isRun)            {                try                {                    DateTime dt = DateTime.Now;                                        for (int i = 0; i < tds.Tables[0].Rows.Count; i++)                    {                        tds.Tables[0].Rows[i][0] = dt;                    }                    Trace.WriteLine("[GAS]: begin update NowXcData!");                    tAdapter.Update(tds.Tables[0]);                    Trace.WriteLine("[GAS]: end update NowXcData!");                    Thread.Sleep(1000);                }                catch(Exception ex)                {                    MessageBox.Show(ex.Message);                }            }        }