SQL Server刪除性能問題

Question

我有一張約有100萬行的表。 我們的部分維護工作涉及每天刪除舊行，但這大約需要40分鍾。

delete語句為：

DELETE 
  FROM [dbGlobalPricingMatrix].[dbo].[tblPricing]
  WHERE type = 'car'
  AND capid NOT IN
  (SELECT cder_id  FROM PUB_CAR.dbo.CapDer WHERE cder_discontinued 
IS NULL OR DATEDIFF(dd,cder_discontinued,GETDATE()) <= 7)
  AND source = @source

我有什么辦法可以改善性能？

謝謝

按照要求：

CREATE TABLE [dbo].[tblPricing](
[id] [int] IDENTITY(1,1) NOT NULL,
[type] [varchar](50) NULL,
[capid] [int] NULL,
[source] [varchar](50) NULL,
[product] [varchar](50) NULL,
[term] [int] NULL,
[milespa] [int] NULL,
[maintained] [bit] NULL,
[price] [money] NULL,
[created] [datetime] NULL,
[updated] [datetime] NULL,
[notes] [varchar](1000) NULL,
[painttype] [char](1) NULL,
[activeflag] [bit] NULL,
[DealerId] [int] NULL,
[FunderId] [int] NULL,
[IsSpecial] [bit] NULL,
[username] [varchar](50) NULL,
[expiry] [datetime] NULL,
 CONSTRAINT [PK_tblPricing] PRIMARY KEY CLUSTERED 
(
[id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY =   OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]
) ON [PRIMARY]

---

CREATE TABLE [dbo].[CAPDer](
[cder_ID] [int] NOT NULL,
[cder_capcode] [char](20) NULL,
[cder_mancode] [int] NULL,
[cder_rancode] [int] NULL,
[cder_modcode] [int] NULL,
[cder_trimcode] [int] NULL,
[cder_name] [varchar](50) NULL,
[cder_introduced] [datetime] NULL,
[cder_discontinued] [datetime] NULL,
[cder_orderno] [int] NULL,
[cder_vehiclesector] [tinyint] NULL,
[cder_doors] [tinyint] NULL,
[cder_drivetrain] [char](1) NULL,
[cder_fueldelivery] [char](1) NULL,
[cder_transmission] [char](1) NULL,
[cder_fueltype] [char](1) NULL,
 CONSTRAINT [PK_CapDer] PRIMARY KEY CLUSTERED 

（[cder_ID] ASC）（（PAD_INDEX = OFF，STATISTICS_NORECOMPUTE = OFF，IGNORE_DUP_KEY = OFF，ALLOW_ROW_LOCKS = ON，ALLOW_PAGE_LOCKS = ON，FILLFACTOR = 90），ON [PRIMARY]）ON [PRIMARY]

Answer 1

好的，正如我所懷疑的，您似乎沒有在DELETE查詢中引用的字段的索引。 因此，添加索引type ， capid ， cder_discontinued和source 。

另外，您可能想嘗試AND capid IN (SELECT cder_id FROM PUB_CAR.dbo.CapDer WHERE cder_discontinued IS NOT NULL AND DATEDIFF(dd,cder_discontinued,GETDATE()) > 7) 。 MS-SQL-Server的優化器實際上應該為您執行此操作，但您永遠不知道，值得嘗試。