sql-server-2005 - 从 .NET 应用程序到 SQL Server 的偶尔缓慢的调用

Question

我在 SQL Server 中有一个表，它是从仍在生产中的遗留系统继承而来的，该系统根据以下代码构建。我创建了一个 SP 来查询表，如表创建语句下方的代码中所述。我的问题是，通过 Enterprise Library 4 和 DataReader 对象从 .NET 到此 SP 的调用偶尔会很慢。 SP 通过数据层中的循环结构调用，该结构指定进入 SP 以填充用户对象的参数。值得一提的是，不会在每次通过循环结构时都进行慢速调用。它通常会在一天或更长时间的大部分时间里都很好，然后开始展示，这使得调试变得非常困难。

有问题的表包含大约 500 万行。例如，缓慢的调用将需要长达 10 秒的时间，而快速的调用平均需要 0 到 10 毫秒。我在慢速调用期间检查了锁定/阻塞事务，没有找到。我在数据层创建了一些自定义性能计数器来监控调用时间。从本质上讲，当性能很差时，这对那个电话来说真的很糟糕。但是当它很好时，它真的很好。我已经能够在几台不同的开发人员机器上重现该问题，但不能在我们的开发和暂存数据库服务器上重现，这些服务器当然具有更强大的硬件。通常，通过重新启动 SQL Server 服务可以解决问题，但并非总是如此。表上有我正在查询的字段的索引，但是索引比我想要的要多。但是，由于它可能对遗留系统产生影响，我不愿删除任何索引或玩具。以前有没有人遇到过这样的问题，或者您有解决方法的建议吗？

CREATE TABLE [dbo].[product_performance_quarterly](
    [performance_id] [int] IDENTITY(1,1) NOT FOR REPLICATION NOT NULL,
    [product_id] [int] NULL,
    [month] [int] NULL,
    [year] [int] NULL,
    [performance] [decimal](18, 6) NULL,
    [gross_or_net] [char](15) NULL,
    [vehicle_type] [char](30) NULL,
    [quarterly_or_monthly] [char](1) NULL,
    [stamp] [datetime] NULL CONSTRAINT [DF_product_performance_quarterly_stamp]  DEFAULT (getdate()),
    [eA_loaded] [nchar](10) NULL,
    [vehicle_type_id] [int] NULL,
    [yearmonth] [char](6) NULL,
    [gross_or_net_id] [tinyint] NULL,
 CONSTRAINT [PK_product_performance_quarterly_4_19_04] PRIMARY KEY CLUSTERED 
(
    [performance_id] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON, FILLFACTOR = 80) ON [PRIMARY]
) ON [PRIMARY]

GO
SET ANSI_PADDING OFF
GO
ALTER TABLE [dbo].[product_performance_quarterly]  WITH NOCHECK ADD  CONSTRAINT [FK_product_performance_quarterlyProduct_id] FOREIGN KEY([product_id])
REFERENCES [dbo].[products] ([product_id])
GO
ALTER TABLE [dbo].[product_performance_quarterly] CHECK CONSTRAINT [FK_product_performance_quarterlyProduct_id]

CREATE PROCEDURE [eA.Analytics.Calculations].[USP.GetCalculationData]
(
    @PRODUCTID INT,                     --products.product_id
    @BEGINYEAR INT,                     --year to begin retrieving performance data
    @BEGINMONTH INT,                    --month to begin retrieving performance data
    @ENDYEAR INT,                       --year to end retrieving performance data
    @ENDMONTH INT,                      --month to end retrieving performance data
    @QUARTERLYORMONTHLY VARCHAR(1),     --do you want quarterly or monthly data?
    @VEHICLETYPEID INT,                 --what product vehicle type are you looking for?
    @GROSSORNETID INT                   --are your looking gross of fees data or net of fees data?
)
AS
BEGIN

    SET NOCOUNT ON

    DECLARE @STARTDATE VARCHAR(6),
            @ENDDATE   VARCHAR(6),
            @vBEGINMONTH VARCHAR(2),
            @vENDMONTH VARCHAR(2)   

IF LEN(@BEGINMONTH) = 1 
    SET @vBEGINMONTH = '0' + CAST(@BEGINMONTH AS VARCHAR(1))
ELSE
    SET @vBEGINMONTH = @BEGINMONTH

IF LEN(@ENDMONTH) = 1
    SET @vENDMONTH = '0' + CAST(@ENDMONTH AS VARCHAR(1))
ELSE
    SET @vENDMONTH = @ENDMONTH

SET @STARTDATE = CAST(@BEGINYEAR AS VARCHAR(4)) + @vBEGINMONTH
SET @ENDDATE = CAST(@ENDYEAR AS VARCHAR(4)) + @vENDMONTH

--because null values for gross_or_net_id and vehicle_type_id are represented in 
--multiple ways (true null, empty string, or 0) in the PPQ table, need to account for all possible variations if 
--a -1 is passed in from the .NET code, which represents an enumerated value that
--indicates that the value(s) should be true null.

IF @VEHICLETYPEID = '-1' AND @GROSSORNETID = '-1'
    SELECT
        PPQ.YEARMONTH, PPQ.PERFORMANCE
    FROM PRODUCT_PERFORMANCE_QUARTERLY PPQ
        WITH (NOLOCK)
    WHERE 
        (PPQ.PRODUCT_ID = @PRODUCTID)
        AND (PPQ.YEARMONTH BETWEEN @STARTDATE AND @ENDDATE)
        AND (PPQ.QUARTERLY_OR_MONTHLY = @QUARTERLYORMONTHLY)
        AND (PPQ.VEHICLE_TYPE_ID IS NULL OR PPQ.VEHICLE_TYPE_ID = '0' OR PPQ.VEHICLE_TYPE_ID = '')
        AND (PPQ.GROSS_OR_NET_ID IS NULL OR PPQ.GROSS_OR_NET_ID = '0' OR PPQ.GROSS_OR_NET_ID = '')
    ORDER BY PPQ.YEARMONTH ASC

IF @VEHICLETYPEID <> '-1' AND @GROSSORNETID <> '-1'
    SELECT
        PPQ.YEARMONTH, PPQ.PERFORMANCE
    FROM PRODUCT_PERFORMANCE_QUARTERLY PPQ
        WITH (NOLOCK)
    WHERE 
        (PPQ.PRODUCT_ID = @PRODUCTID)
        AND (PPQ.YEARMONTH BETWEEN @STARTDATE AND @ENDDATE)
        AND (PPQ.QUARTERLY_OR_MONTHLY = @QUARTERLYORMONTHLY)
        AND (PPQ.VEHICLE_TYPE_ID = @VEHICLETYPEID )
        AND (PPQ.GROSS_OR_NET_ID = @GROSSORNETID)
    ORDER BY PPQ.YEARMONTH ASC

IF @VEHICLETYPEID = '-1' AND @GROSSORNETID <> '-1'
    SELECT
        PPQ.YEARMONTH, PPQ.PERFORMANCE
    FROM PRODUCT_PERFORMANCE_QUARTERLY PPQ
        WITH (NOLOCK)
    WHERE 
        (PPQ.PRODUCT_ID = @PRODUCTID)
        AND (PPQ.YEARMONTH BETWEEN @STARTDATE AND @ENDDATE)
        AND (PPQ.QUARTERLY_OR_MONTHLY = @QUARTERLYORMONTHLY)
        AND (PPQ.VEHICLE_TYPE_ID IS NULL OR PPQ.VEHICLE_TYPE_ID = '0' OR PPQ.VEHICLE_TYPE_ID = '')
        AND (PPQ.GROSS_OR_NET_ID = @GROSSORNETID)
    ORDER BY PPQ.YEARMONTH ASC

IF @VEHICLETYPEID <> '-1' AND @GROSSORNETID = '-1'
    SELECT
        PPQ.YEARMONTH, PPQ.PERFORMANCE
    FROM PRODUCT_PERFORMANCE_QUARTERLY PPQ
        WITH (NOLOCK)
    WHERE 
        (PPQ.PRODUCT_ID = @PRODUCTID)
        AND (PPQ.YEARMONTH BETWEEN @STARTDATE AND @ENDDATE)
        AND (PPQ.QUARTERLY_OR_MONTHLY = @QUARTERLYORMONTHLY)
        AND (PPQ.VEHICLE_TYPE_ID = @VEHICLETYPEID)
        AND (PPQ.GROSS_OR_NET_ID IS NULL OR PPQ.GROSS_OR_NET_ID = '0' OR PPQ.GROSS_OR_NET_ID = '')
    ORDER BY PPQ.YEARMONTH ASC

END

Answer 1

我已经看到过时的索引会发生这种情况。它也可能是参数嗅探问题，其中不同的查询计划被用于进入存储过程的不同参数。

您应该捕获慢速调用的参数，并在每次运行缓慢时查看它们是否相同。

您也可以尝试运行调整向导，看看它是否推荐任何索引。

在您可以证明更新和插入发生得太慢(修改索引加上锁定/争用所需的时间)或者您的磁盘空间不足之前，您不想担心索引过多。