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と呼ばれる2つのテーブル"Users(60,0000 records),UserBasicInfo(60,0000 records)"があります.Usersテーブルには、UsersID列にクラスター化されたインデックスがあります.UserBasicInfoテーブルには、UsersID FKポイントがUsersテーブルUsersID列を指し、列に非クラスター化がありUpdateTime,UsersIDます.

CREATE TABLE [dbo].[Users](
    [UsersID] [int] IDENTITY(100000,1) NOT NULL,
    [LoginUsersName] [nvarchar](50) NOT NULL,
    [LoginUsersPwd] [nvarchar](50) NOT NULL,
    [Email] [nvarchar](80) NOT NULL,
    [IsEnable] [int] NOT NULL,
    [CreateTime] [datetime] NOT NULL,
    [LastLoginTime] [datetime] NOT NULL,
    [LastLoginIp] [nvarchar](50) NOT NULL,
    [UpdateTime] [datetime] NOT NULL,
 CONSTRAINT [PK_Users] PRIMARY KEY CLUSTERED 
(
    [UsersID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]


CREATE TABLE [dbo].[UserBasicInfo](
    [UserBaicInfoID] [int] IDENTITY(1,1) NOT NULL,
    [UsersID] [int] NOT NULL,
    [ResumePoints] [nvarchar](50) NOT NULL,
    [IsChineseOrEnglish] [int] NOT NULL,
    [UserName] [nvarchar](50) NOT NULL,
    [Sex] [int] NOT NULL,
    [Height] [int] NOT NULL,
    [Birthday] [datetime] NOT NULL,
    [Age] [int] NOT NULL,
    [IDCard] [nvarchar](50) NOT NULL,
    [IsMarryed] [int] NOT NULL,
    [NativePlace] [nvarchar](50) NOT NULL,
    [PoliticalStatus] [int] NOT NULL,
    [CurrentAddress] [nvarchar](50) NOT NULL,
    [CurrentAddressDetail] [nvarchar](50) NOT NULL,
    [WorkExperience] [int] NOT NULL,
    [HighestEducation] [int] NOT NULL,
    [LogoPath] [nvarchar](200) NULL,
    [MobilePhone] [nvarchar](50) NOT NULL,
    [Phone] [nvarchar](50) NULL,
    [QQ] [nvarchar](50) NULL,
    [Blog] [nvarchar](300) NULL,
    [MicroBlog] [nvarchar](300) NULL,
    [PositionDesired] [nvarchar](100) NOT NULL,
    [IndustrySmallClass] [nvarchar](100) NULL,
    [PositionName] [nvarchar](100) NOT NULL,
    [PositionType] [int] NOT NULL,
    [WorkAddressLarge] [int] NOT NULL,
    [WorkAddressSmall] [nvarchar](200) NOT NULL,
    [WorkAddressSmallText] [nvarchar](100) NOT NULL,
    [Salary] [int] NOT NULL,
    [HousingRequirement] [int] NOT NULL,
    [ToWorkTime] [int] NOT NULL,
    [ResumeState] [int] NOT NULL,
    [IsSystemAdd] [int] NOT NULL,
    [CreateTime] [datetime] NOT NULL,
    [UpdateTime] [datetime] NOT NULL,
    [RefreshDateTime] [datetime] NOT NULL,
    [RefreshTime] [int] NOT NULL,
    [TotalTime] [int] NOT NULL,
 CONSTRAINT [PK_UserBasicInfo] PRIMARY KEY CLUSTERED 
(
    [UserBaicInfoID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]
ALTER TABLE [dbo].[UserBasicInfo]  WITH CHECK ADD  CONSTRAINT [FK_UserBasicInfo_Users] FOREIGN KEY([UsersID])
REFERENCES [dbo].[Users] ([UsersID])

ただし、低速で実行します。

DBCC DROPCLEANBUFFERS   
DBCC FREEPROCCACHE
SELECT TOP 100 * FROM Users U INNER JOIN UserBasicInfo UB ON UB.UsersID=U.UsersID ORDER BY UB.UpdateTime DESC

SQL Server Execution Times:
   CPU time = 16 ms,  elapsed time = 3568 ms.

ここに画像の説明を入力 次に、以下を高速に実行します。

SELECT TOP 100 * FROM Users U INNER JOIN UserBasicInfo UB ON UB.UsersID=U.UsersID ORDER BY UB.UpdateTime DESC

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 163 ms.

ここに画像の説明を入力

正常ですか？

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1 に答える 1

1

はい、正常です

2 つの DBCC コマンドで、クエリ プランとキャッシュ データが削除されました。おそらく主なオーバーヘッドは、データをディスクから再度読み取る必要があることです。

追加SET STATISTICS IO ONすると、データがディスクから読み込まれるため、DBCC の後に「物理ページ読み取り」と「先読み読み取り」がさらに表示されます

私はそれらを実行することはほとんどありません。詳細については、これらの dba.se の質問を参照してください。

于 2013-06-27T08:39:36.387 に答える