执行计划与ROW_NUMBER

Question

我正在尝试微调使用带有ROW_NUMBER个PARTITION BY参数的SELECT SDP.SuspectID ,SDP.RecordID ,SDP.Field ,SDP.FieldEntryDate ,SDP.ScreenDate ,SDP.SuspectDetails ,CONVERT(VARCHAR(10),SDP.PeriodEndDate,120) AS PeriodEndDate ,ROW_NUMBER() OVER (PARTITION BY SDP.recordID, SDP.Field, SDP.ScreenerID, SDP.PeriodEndDate, SDP.PeriodID, SDP.[Source], SDP.SuspectDetails ORDER BY SDP.UploadDate) AS RowNum ,SDP.DatabaseAccountCode ,SDP.RecordUpdateType INTO #Temp FROM dbo.SuspectDataPoint AS SDP LEFT JOIN dbo.Screener AS S ON S.screenerID = SDP.screenerID WHERE SDP.ScreenerId not in (719) AND S.DatabaseName = 'db' AND CONVERT(DATE, SDP.FieldEntryDate) > DATEADD(dd,-24,GETDATE()) 的查询来从db获取唯一记录。查询与下面完全相同：

ROW_NUMBER

我尝试手动查找此查询中效率最低的部分，结果表明它与ROW_NUMBER的运行时间比没有它的情况长10倍。

我还试图检查执行计划以确认发现，但有些事情我不明白。如果我按上面给出的那样运行查询，执行计划会显示最大的成本是插入临时表（45％）。当我在没有ROW_NUMBER行的情况下运行相同的查询时，情况也是这样，只是％相差一点（61％）。我理解在第一个查询中，SORT操作发生在ROW_NUMBER，但与其他查询相比，它相当便宜（25％）。然而，正如我所说，没有和/****** Object: Table [dbo].[Screener] Script Date: 10/17/2014 5:53:51 PM ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_PADDING ON GO CREATE TABLE [dbo].[Screener]( [ScreenerID] [int] NOT NULL, [ScreenerName] [varchar](255) NOT NULL, [ScreenerDescription] [nvarchar](4000) NULL, [Script] [text] NULL, [HitRate] [numeric](10, 2) NOT NULL DEFAULT ((1)), [CreatedOn] [date] NULL, [CreatedBy] [varchar](7) NULL, [SuspectReason] [nvarchar](4000) NULL, [IsExtremeOutlier] [bit] NOT NULL DEFAULT ((0)), [DatabaseName] [varchar](20) NOT NULL, PRIMARY KEY CLUSTERED ( [ScreenerID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY] GO SET ANSI_PADDING OFF GO /****** Object: Table [dbo].[SuspectDataPoint] Script Date: 10/17/2014 5:53:52 PM ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_PADDING ON GO CREATE TABLE [dbo].[SuspectDataPoint]( [SuspectID] [int] IDENTITY(1,1) NOT FOR REPLICATION NOT NULL, [RecordID] [varchar](30) NOT NULL, [Field] [varchar](50) NOT NULL, [ScreenerID] [int] NOT NULL, [ScreenDate] [datetime] NOT NULL, [SuspectDetails] [nvarchar](4000) NULL, [PeriodEndDate] [datetime] NULL, [FieldEntryDate] [datetime] NOT NULL, [OriginalValue] [nvarchar](4000) NULL, [Source] [nvarchar](300) NULL, [UniqueSystemID] [int] NOT NULL, [DatabaseAccountCode] [varchar](50) NULL, [RecordUpdateType] [varchar](60) NULL, [UploadDate] [datetime] NOT NULL DEFAULT (getdate()), [PeriodID] [varchar](20) NULL, PRIMARY KEY CLUSTERED ( [SuspectID] 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 SET ANSI_PADDING OFF GO SET ANSI_PADDING ON GO /****** Object: Index [in_n_Screener_DatabaseName] Script Date: 10/17/2014 5:53:52 PM ******/ CREATE NONCLUSTERED INDEX [in_n_Screener_DatabaseName] ON [dbo].[Screener] ( [DatabaseName] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO SET ANSI_PADDING ON GO /****** Object: Index [in_n_SuspectDataPoint_DatabaseAccountCode] Script Date: 10/17/2014 5:53:52 PM ******/ CREATE NONCLUSTERED INDEX [in_n_SuspectDataPoint_DatabaseAccountCode] ON [dbo].[SuspectDataPoint] ( [DatabaseAccountCode] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO SET ANSI_PADDING ON GO /****** Object: Index [in_n_SuspectDataPoint_Field] Script Date: 10/17/2014 5:53:52 PM ******/ CREATE NONCLUSTERED INDEX [in_n_SuspectDataPoint_Field] ON [dbo].[SuspectDataPoint] ( [Field] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO SET ANSI_PADDING ON GO /****** Object: Index [in_n_SuspectDataPoint_RecordID] Script Date: 10/17/2014 5:53:52 PM ******/ CREATE NONCLUSTERED INDEX [in_n_SuspectDataPoint_RecordID] ON [dbo].[SuspectDataPoint] ( [RecordID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO /****** Object: Index [in_n_SuspectDataPoint_ScreenerID] Script Date: 10/17/2014 5:53:52 PM ******/ CREATE NONCLUSTERED INDEX [in_n_SuspectDataPoint_ScreenerID] ON [dbo].[SuspectDataPoint] ( [ScreenerID] ASC ) INCLUDE ( [ScreenDate]) WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO /****** Object: Index [in_n_SuspectDataPoint_UniqueSystemID] Script Date: 10/17/2014 5:53:52 PM ******/ CREATE NONCLUSTERED INDEX [in_n_SuspectDataPoint_UniqueSystemID] ON [dbo].[SuspectDataPoint] ( [UniqueSystemID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO /****** Object: Index [SuspectDataPoint_FieldEntryDate_Index] Script Date: 10/17/2014 5:53:52 PM ******/ CREATE NONCLUSTERED INDEX [SuspectDataPoint_FieldEntryDate_Index] ON [dbo].[SuspectDataPoint] ( [FieldEntryDate] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO SET ANSI_PADDING ON GO /****** Object: Index [SuspectDataPoint_RecordUpdateType_Index] Script Date: 10/17/2014 5:53:52 PM ******/ CREATE NONCLUSTERED INDEX [SuspectDataPoint_RecordUpdateType_Index] ON [dbo].[SuspectDataPoint] ( [RecordUpdateType] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO /****** Object: Index [SuspectDataPoint_ScreenDate_Index] Script Date: 10/17/2014 5:53:52 PM ******/ CREATE NONCLUSTERED INDEX [SuspectDataPoint_ScreenDate_Index] ON [dbo].[SuspectDataPoint] ( [ScreenDate] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO SET ANSI_PADDING ON GO /****** Object: Index [SuspectDataPoint_Source_Index] Script Date: 10/17/2014 5:53:52 PM ******/ CREATE NONCLUSTERED INDEX [SuspectDataPoint_Source_Index] ON [dbo].[SuspectDataPoint] ( [Source] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO /****** Object: Index [SuspectDataPoint_SuspectID_Index] Script Date: 10/17/2014 5:53:52 PM ******/ CREATE UNIQUE NONCLUSTERED INDEX [SuspectDataPoint_SuspectID_Index] ON [dbo].[SuspectDataPoint] ( [SuspectID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO /****** Object: Index [SuspectDataPoint_UploadDate_Index] Script Date: 10/17/2014 5:53:52 PM ******/ CREATE NONCLUSTERED INDEX [SuspectDataPoint_UploadDate_Index] ON [dbo].[SuspectDataPoint] ( [UploadDate] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO ALTER TABLE [dbo].[Screener] WITH CHECK ADD CONSTRAINT [FK_Screener_DatabaseInfo] FOREIGN KEY([DatabaseName]) REFERENCES [dbo].[DatabaseInfo] ([DatabaseName]) ON UPDATE CASCADE GO ALTER TABLE [dbo].[Screener] CHECK CONSTRAINT [FK_Screener_DatabaseInfo] GO 线的实际时间是非常不同的（1s对13s平均）。任何人都可以向我解释一下吗？我是否错误地阅读了该计划？

编辑：添加索引视图

编辑：添加架构和索引脚本

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Answer 1

我怀疑并行性位正在扭曲执行计划中的百分比。

另一方面，“计算标量”发生在“with ROW_NUMBER”计划中的并行排序之后，这可能意味着

CONVERT(DATE, SDP.FieldEntryDate) > DATEADD(dd,-24,GETDATE())

在Row_Number OVER子句之后发生了where子句的一部分。如果该WHERE子句排除了SPD表的重要部分，那么这将解释为什么OVER子句如此大规模地影响查询。您可以先（先）过滤（ed）然后再运行ROW_NUMBER。