可以优化以下查询

Question

我在下面有一个SQL查询：

DECLARE @Power VARCHAR(10), @Button VARCHAR(10), @Casing VARCHAR(10), @Screen VARCHAR(10)
SELECT @Power = ActivityId FROM t_Activity WHERE ActivityName = 'PhonePowersUp?'
SELECT @Button = ActivityId FROM t_Activity WHERE ActivityName = 'T/S and Buttons functioning OK?'
SELECT @Casing = ActivityId FROM t_Activity WHERE ActivityName = 'Casing - no major defects?'
SELECT @Screen = ActivityId FROM t_Activity WHERE ActivityName = 'LCD works OK?'

SELECT
    HQ.HandsetQuoteId [HandsetQuoteId], SS.Name [quote_status], HQ.QuoteDate [Quote Date], INS.DateInspected [DateInspected], PA.IMEI [IMEI_Quoted],
    PA1.IMEI [IMEI_Inspected],  INS.Grade [Grade], PB.PackageBoxName [PackageBoxName], CC.Name [ContactChannel], PhnBrd.Name [Brand], PM.ModelName [ModelQuoted],
    PM1.ModelName [ModelInspected], U.FirstName [FirstName], U.Surname [Surname], U.Username [Username], UW.WarehouseId [WarehouseId], W.Name [Warehouse Name],
    HQA.Value [Original Quote Value], HQ.QuoteValue [Quote Value], INS.InspectionValue [InspectionValue], HQ.AgreedValue [Agreed Value], CUS.FirstName [Store Name],
    DATEDIFF(DAY, HQ.QuoteDate, GETDATE()) [Quote Age],
    [ST_POWER] = CASE WHEN (CHARINDEX(','+ @Power +',', ','+PAR.Ok+',') > 0) THEN 'YES' WHEN (CHARINDEX(','+ @Power +',', ','+PAR.Fault+',') > 0) THEN 'NO' ELSE NULL END,
    [ST_BUTTONS] = CASE WHEN (CHARINDEX(','+ @Button +',', ','+PAR.Ok+',') > 0) THEN 'YES' WHEN (CHARINDEX(','+ @Button +',', ','+PAR.Fault+',') > 0) THEN 'NO' ELSE NULL END,
    [ST_CASING] = CASE WHEN (CHARINDEX(','+ @Casing +',', ','+PAR.Ok+',') > 0) THEN 'YES' WHEN (CHARINDEX(','+ @Casing +',', ','+PAR.Fault+',') > 0) THEN 'NO' ELSE NULL END,
    [ST_Screen] = CASE WHEN (CHARINDEX(','+ @Screen +',', ','+PAR.Ok+',') > 0) THEN 'YES' WHEN (CHARINDEX(','+ @Screen +',', ','+PAR.Fault+',') > 0) THEN 'NO' ELSE NULL END,
    st_deduct = PAR.PercentageDeduction, wt_deduct = MAX(APD1.PercentageDeduction)
FROM t_Inspection AS INS
INNER JOIN t_HandsetQuote                   HQ      ON HQ.HandsetQuoteId = INS.HandsetQuoteId
INNER JOIN t_QuoteHeader                    QH      ON QH.QuoteHeaderId = HQ.QuoteHeaderId
INNER JOIN t_Customer                       CUS     ON CUS.CustomerId = QH.CustomerId
INNER JOIN t_ContactChannel                 CC      ON CC.ContactChannelId = CUS.ContactChannelId
INNER JOIN t_PackageBoxHandset              PBH     ON PBH.HandsetQuoteId = HQ.HandsetQuoteId
INNER JOIN t_PackageBox                     PB      ON PB.PackageBoxId = PBH.PackageBoxId
INNER JOIN t_PackageBoxStatus               PBS     ON PBS.PackageBoxStatusId = PB.PackageBoxStatusId
INNER JOIN t_StockStatus                    SS      ON SS.StockStatusId = HQ.StockStatusId
INNER JOIN t_QuoteStatus                    QS      ON QS.QuoteStatusId = QH.QuoteStatusId
INNER JOIN t_PhoneAudit                     PA      ON PA.PhoneAuditId = HQ.QuotePhoneAuditId
INNER JOIN t_PhoneModel                     PM      ON PM.PhoneModelId = PA.PhoneModelId AND PA.PhoneAuditId = HQ.QuotePhoneAuditId
INNER JOIN t_PhoneBrand                     PhnBrd  ON PM.PhoneBrandId = PhnBrd.PhoneBrandId
INNER JOIN t_PhoneAudit                     PA1     ON PA1.PhoneAuditId = HQ.InspectionPhoneAuditId
INNER JOIN t_PhoneModel                     PM1     ON PM1.PhoneModelId = PA1.PhoneModelId AND PA1.PhoneAuditId = HQ.InspectionPhoneAuditId
INNER JOIN t_PhoneBrand                     PhnBrd1 ON PM1.PhoneBrandId = PhnBrd1.PhoneBrandId
INNER JOIN t_User                           U       ON INS.InspectorId = U.UserId
INNER JOIN t_UserWarehouse                  UW      ON U.UserId = UW.UserId
INNER JOIN t_Warehouse                      W       ON UW.WarehouseId = W.WarehouseId
LEFT JOIN t_HandsetQuoteAdditionalInfo      HQA     ON HQ.HandsetQuoteId = HQA.HandsetQuoteId AND HQA.KeyName LIKE '%OriginalQuoteValue%'
LEFT JOIN t_PhoneAuditRetail                PAR     ON PAR.HandsetQuoteId = HQ.HandsetQuoteId
LEFT JOIN t_Activity_PercentageDeduction    APD     ON APD.ActivityPercentageDeductionId = PAR.DeductionTypeId
LEFT JOIN t_HandsetQuoteActivity            HQA1    ON HQA1.HandsetQuoteId = HQ.HandsetQuoteId AND HQA1.activitystarttime = (
                                        CASE
                                            WHEN ((SELECT Count(1) FROM t_HandsetQuoteActivity WHERE  HandsetQuoteId = HQA1.HandsetQuoteId AND ActivityStartTime <= QH.Cache_QuoteAcceptedDate AND ActivityId = HQA1.ActivityId) > 0)
                                            THEN (SELECT Max(ActivityStartTime) FROM t_HandsetQuoteActivity WHERE HandsetQuoteId = HQA1.HandsetQuoteId AND ActivityStartTime <= QH.Cache_QuoteAcceptedDate AND ActivityId = HQA1.ActivityId GROUP BY HandsetQuoteId, ActivityId)
                                        ELSE
                                            (SELECT Min(ActivityStartTime) FROM t_HandsetQuoteActivity WHERE HandsetQuoteId = HQA1.HandsetQuoteId AND ActivityStartTime >= QH.Cache_QuoteAcceptedDate AND ActivityId = HQA1.ActivityId GROUP BY HandsetQuoteId, ActivityId)
                                        END)
LEFT JOIN t_Activity_PercentageDeduction    APD1    ON APD1.ActivityId = HQA1.ActivityId
LEFT JOIN t_PhoneAuditRetail                PAR1    ON PAR1.HandsetQuoteId = HQA1.HandsetQuoteId AND PAR1.HandsetQuoteId = HQ.HandsetQuoteId
WHERE Ins.DateInspected > GETDATE()-90
GROUP BY HQ.HandsetQuoteId, SS.Name, QH.CreatedDate, INS.DateInspected, PA.IMEI, PA1.IMEI, INS.Grade, PB.PackageBoxName, CC.Name, PhnBrd.Name, PM.ModelName, PM1.ModelName,
U.FirstName, U.Surname, U.Username, UW.WarehouseId, W.Name, HQA.Value, HQ.QuoteValue, INS.InspectionValue, HQ.AgreedValue, CUS.Firstname, HQ.QuoteDate, PAR.Ok, PAR.Fault,
PAR.PercentageDeduction

这是一个Select查询，它只选择不多的记录，但是此查询选择的记录超过100万条，因此显示数据需要30分钟以上。

我需要您的帮助，以了解如何对其进行优化。

附件是具有最大数据的表设计的屏幕截图：

Answer 1

我只是去索引视图。 索引视图就像将查询结果存储在硬盘驱动器上，然后让SQL Server自动将其保持最新。 然后，您可以在此索引视图上运行简单得多的查询，并节省大量时间。 只需注意存储空间，因为它是基础数据库中某些数据的物理副本！ （多少取决于它基于SELECT查询的排他性）

-- Create a view from the query
CREATE VIEW dbo.HandsetView
WITH SCHEMABINDING
AS
--**** Original query goes here
GO

它说“原始查询在这里”，您可以在其中放置当前查询。 唯一的是，我要么想出一种方法来更改查询，所以您不必声明这样的变量，否则就不得不将索引过滤掉的部分留在索引视图之外。 当然，您可以稍后使用它们查询索引视图，但是它的性能可能不尽如人意。 您还应该在WHERE子句中省略GETDATE()谓词，并在查询视图时将其保存。

-- Index the view
CREATE UNIQUE CLUSTERED INDEX idx_cl_handset_view
ON dbo.HandsetView(DateInspected);
GO

这使您可以查询物理存储在磁盘上的视图，因此是预先计算的：

-- Re-run query, this time using the indexed view.
SELECT   *
FROM     dbo.HandsetView WITH (NOEXPAND)
WHERE    HandsetView.DateInspected > GETDATE() - 90;

上面是建立索引视图后如何查询的方法。 您可以像查询普通表一样对其进行查询，但是如果不使用SQL Server Enterprise，请确保具有WITH (NOEXPAND)选项，否则SQL优化器将查询基础表，从而抵消其任何性能优势。这个。

索引视图可能有点挑剔，因此请确保您跳过此MSDN文章中有关索引视图的描述 。