Question

我的问题开始于Entity Framework查询的执行非常缓慢（〜2分钟）。所以我开始调查

与此同时，该问题似乎也在标准SqlConnection

中

我有一个非常简单的查询

SELECT 1 AS [C1], [Extent1].[OldReleaseID] AS [OldReleaseID], [Extent1].[ProductName] AS [ProductName], [Extent1].[Price] AS [Price], [Extent1].[DiscountAmount] AS [DiscountAmount], [Extent1].[DiscountRate] AS [DiscountRate], [Extent1].[AbsorbVat] AS [AbsorbVat], [Extent1].[SerialCode] AS [SerialCode], [Extent1].[BrandName] AS [BrandName] FROM [dbo].[LocalSaleProductExts]() AS [Extent1]

当我在SSMS中运行它时，它会在0-1秒内执行并返回约3万行

同一精确查询在.net ExecuteReader中运行大约100秒！

在线研究基本上指出了两种解决方案：ARITHABORT和参数嗅探，因此，对于踢球，我在SSMS中添加了所有这些解决方案

DBCC FREESESSIONCACHE
DBCC FREEPROCCACHE
SET ARITHABORT OFF

仍然0-1秒。

然后在我的代码中添加了SET ARITHABORT ON。这是我的简单代码

Using sc = New SqlClient.SqlConnection("data source=MYHOST;initial catalog=MYDB;persist security info=True;user id=MYUSER;password=MYPASS;MultipleActiveResultSets=True;")
       Dim txt = "SELECT 1 AS [C1], [Extent1].[OldReleaseID] AS [OldReleaseID], [Extent1].[ProductName] AS [ProductName], [Extent1].[Price] AS [Price], [Extent1].[DiscountAmount] AS [DiscountAmount], [Extent1].[DiscountRate] AS [DiscountRate], [Extent1].[AbsorbVat] AS [AbsorbVat], [Extent1].[SerialCode] AS [SerialCode], [Extent1].[BrandName] AS [BrandName] FROM [dbo].[LocalSaleProductExts]() AS [Extent1] OPTION (RECOMPILE)"
        sc.Execute("SET ARITHABORT ON")
        sc.TryOpen()
        Dim ret As List(Of Common.DbDataRecord)
        Using cmd = sc.CreateCommand(txt)
            Using dr = cmd.ExecuteReader
                ret = dr.Cast(Of Common.DbDataRecord).ToList
                dr.Close()
            End Using
        End Using
        Dim a = ret
    End Using

我认为参数嗅探在这里是无关紧要的，因为我没有发送任何参数

这也不是一个阻碍性的问题，因为我正在同时测试它们（尽可能多地...），因此，如果这是一个计时问题，两者都应该很慢

那问题又是什么呢？

非常感谢

ExecuteReader比SSMS慢得多

0 个答案: