按連接表的性能問題排序

Question

我有兩個表：「報警」和「設備」和視圖「vwAlarms」 報警表有250K行，設備表只有50行。

vwAlarms只是兩個表的連接。

我的問題是當我添加Top（x）和命令ID desc從vwAlarm中選擇*需要10秒鐘來執行查詢。然而相同的查詢在表格報警上快速運行。

select * from Alarm --in milliseconds. 
select * from vwAlarms --in milliseconds 
select top (100) * from Alarms order by id desc --in milliseconds 
select top (100) * from vwAlarms order by id desc --takes 10 seconds 

這裏是我的視圖的定義：

CREATE VIEW [dbo].[vwAlarms] 
AS SELECT 
    dbo.Devices.Id , 
    dbo.Devices.Name , 
    dbo.Devices.PortsTagPrefix , 
    dbo.Devices.ControlCenterNumber , 
    dbo.Devices.AlarmNumber1 , 
    dbo.Devices.AlarmNumber2 , 
    dbo.Devices.SimCardNumber , 
    dbo.Devices.StationNumber , 
    dbo.Devices.SlaveId , 
    dbo.Devices.TypeId , 
    dbo.Devices.RegionId , 
    dbo.Devices.EnquiryPassword , 
    dbo.Devices.SetupPassword , 
    dbo.Devices.ProtocolId , 
    dbo.Devices.UploadedPacketsCount , 
    dbo.Devices.LastPort , 
    dbo.Devices.LastIp , 
    dbo.Devices.IsForTesting , 
    dbo.Devices.Latitude , 
    dbo.Devices.Longitude , 
    dbo.Devices.X , 
    dbo.Devices.Y , 
    dbo.Devices.MainSchematicId , 
    dbo.Devices.MainTimeChartId , 
    dbo.Devices.MainCategoryChartId , 
    dbo.Alarms.Id , 
    dbo.Alarms.DeviceId , 
    dbo.Alarms.LogId , 
    dbo.Alarms.PortId , 
    dbo.Alarms.TypeId , 
    dbo.Alarms.DateTime , 
    dbo.Alarms.AcknowledgerId , 
    dbo.Alarms.AcknowledgeDateTime , 
    dbo.Alarms.Acknowledged , 
    dbo.Alarms.PortValue 
FROM Devices 
     INNER JOIN Alarms ON Devices.Id = Alarms.DeviceId 
ORDER BY dbo.Alarms.Id DESC 

下面是執行計劃：排序

警告消息：

報警表模式：

CREATE TABLE [dbo].[Alarms](
[Id] [int] IDENTITY(1,1) NOT NULL, 
[DeviceId] [int] NOT NULL, 
[LogId] [int] NOT NULL, 
[PortId] [int] NOT NULL, 
[TypeId] [int] NOT NULL, 
[DateTime] [datetime2](0) NOT NULL, 
[AcknowledgerId] [int] NULL, 
[AcknowledgeDateTime] [datetime2](0) NULL, 
[Acknowledged] [bit] NULL, 
[PortValue] [numeric](19, 4) NULL, 
CONSTRAINT [PK_Alarms] PRIMARY KEY CLUSTERED 
(
    [Id] ASC 
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] 
) ON [PRIMARY] 

GO 

ALTER TABLE [dbo].[Alarms] WITH CHECK ADD CONSTRAINT [FK_Alarms_AlarmTypes] FOREIGN KEY([TypeId]) 
REFERENCES [dbo].[AlarmTypes] ([Id]) 
GO 

ALTER TABLE [dbo].[Alarms] CHECK CONSTRAINT [FK_Alarms_AlarmTypes] 
GO 

ALTER TABLE [dbo].[Alarms] WITH CHECK ADD CONSTRAINT [FK_Alarms_Devices] FOREIGN KEY([DeviceId]) 
REFERENCES [dbo].[Devices] ([Id]) 
GO 

ALTER TABLE [dbo].[Alarms] CHECK CONSTRAINT [FK_Alarms_Devices] 
GO 

ALTER TABLE [dbo].[Alarms] WITH CHECK ADD CONSTRAINT [FK_Alarms_ExtendedUsers] FOREIGN KEY([AcknowledgerId]) 
REFERENCES [dbo].[ExtendedUsers] ([Id]) 
GO 

ALTER TABLE [dbo].[Alarms] CHECK CONSTRAINT [FK_Alarms_ExtendedUsers] 
GO 

ALTER TABLE [dbo].[Alarms] WITH CHECK ADD CONSTRAINT [FK_Alarms_Logs] FOREIGN KEY([LogId]) 
REFERENCES [dbo].[Logs] ([Id]) 
ON UPDATE CASCADE 
ON DELETE CASCADE 
GO 

ALTER 

Answer 1

這不是很聰明。
您是否定義了FK？

我會嘗試連接上的表提示的所有選項，以嘗試更早的推送。

Join Hints (Transact-SQL)

如果表提示不工作，我會嘗試跨應用。
我認爲交叉應用應該聰明點。
但代價是沒有像「加入」一樣快。
因此，它可以很好地返回前1000或10,000，但不好。

SELECT t1.*, t2o.* 
FROM t1 
CROSS APPLY 
     (
     SELECT * 
     FROM t2 
     WHERE t2.t1_id = t1.id 
     ) t2o 

Answer 2

正在使用視圖必須？如果沒有，你可能應該先獲得100個警報，然後加入設備。這是你想要的最終結果？