[VB.NET][Windows Form] 錯誤訊息System.Exception: Execution Timeout Expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

錯誤訊息

************** Exception Text **************

System.Exception: Execution Timeout Expired.  The timeout period elapsed prior to completion of the operation or the server is not responding.

原本使用的SQL連線方式如下

 Dim Ds As New DataSet
 Conn = New SqlConnection(connStr)
 Dim records As New List(Of GUIDO)
 Dim SqlTxt As String = ""
 SqlTxt += " SELECT * "
 SqlTxt += " FROM TESTTABLE "
 Dim Cmmd As New SqlCommand(SqlTxt, Conn)
 Conn.Open()
 Dim Da As New SqlDataAdapter(Cmmd)
 Da.Fill(Ds)

後來發現Timeout 的原因為預設30秒，剛好這一段SQL 真的屬於比較複雜，所以我就針對這一段SQL加長timeout的預設值到120

就快速解決問題了

 Dim Ds As New DataSet
 Conn = New SqlConnection(connStr)
 Dim records As New List(Of GUIDO)
 Dim SqlTxt As String = ""
 SqlTxt += " SELECT * "
 SqlTxt += " FROM TESTTABLE "
 Dim Cmmd As New SqlCommand(SqlTxt, Conn)
 Conn.Open()
 Dim Da As New SqlDataAdapter(Cmmd)
Da.SelectCommand.CommandTimeout = 120
 Da.Fill(Ds)

-後續追蹤-
發現DB 因為最近都沒有執行rebulid index ,所以開始造成查詢緩慢的現象
緊急先將幾個重要的table 執行rebulid後
隔天狀況有改善了,不過最好還是在每天備份的時候順便排程執行rebulid index 會比較好
後續再來分享立即rebulid 的方式 跟 排程rebulid