--------------索引的使用-------------

 A. 使用簡單索引
下面的示例爲 authors 表的 au_id 列創建索引。

SET NOCOUNT OFF
USE pubs
IF EXISTS ( SELECT name FROM sysindexes
     
WHERE name = ' au_id_ind ' )
  
DROP INDEX authors.au_id_ind
GO
USE pubs
CREATE INDEX au_id_ind
  
ON authors (au_id)
GO

B. 使用唯一聚集索引
下面的示例爲 emp_pay 表的 employeeID 列創建索引,並且強制唯一性。因爲指定了
CLUSTERED 子句,所以該索引將對磁盤上的數據進行物理排序。

SET NOCOUNT ON
USE pubs
IF EXISTS ( SELECT * FROM INFORMATION_SCHEMA.TABLES
     
WHERE TABLE_NAME = ' emp_pay ' )
  
DROP TABLE emp_pay
GO
USE pubs
IF EXISTS ( SELECT name FROM sysindexes
     
WHERE name = ' employeeID_ind ' )
  
DROP INDEX emp_pay.employeeID_ind
GO
USE pubs
GO
CREATE TABLE emp_pay
(
employeeID
int NOT NULL ,
base_pay
money NOT NULL ,
commission
decimal ( 2 , 2 ) NOT NULL
)
INSERT emp_pay
  
VALUES ( 1 , 500 , . 10 )
INSERT emp_pay
  
VALUES ( 2 , 1000 , . 05 )
INSERT emp_pay
  
VALUES ( 3 , 800 , . 07 )
INSERT emp_pay
  
VALUES ( 5 , 1500 , . 03 )
INSERT emp_pay
  
VALUES ( 9 , 750 , . 06 )
GO
SET NOCOUNT OFF
CREATE UNIQUE CLUSTERED INDEX employeeID_ind
  
ON emp_pay (employeeID)
GO C. 使用簡單組合索引 下面的示例爲 order_emp 表的 orderID 列和 employeeID 列創建索引。 SET NOCOUNT ON
USE pubs
IF EXISTS ( SELECT * FROM INFORMATION_SCHEMA.TABLES
     
WHERE TABLE_NAME = ' order_emp ' )
  
DROP TABLE order_emp
GO
USE pubs
IF EXISTS ( SELECT name FROM sysindexes
     
WHERE name = ' emp_order_ind ' )
  
DROP INDEX order_emp.emp_order_ind
GO
USE pubs
GO
CREATE TABLE order_emp
(
orderID
int IDENTITY ( 1000 , 1 ),
employeeID
int NOT NULL ,
orderdate
datetime NOT NULL DEFAULT GETDATE (),
orderamount
money NOT NULL
)

INSERT order_emp (employeeID, orderdate, orderamount)
  
VALUES ( 5 , ' 4/12/98 ' , 315.19 )
INSERT order_emp (employeeID, orderdate, orderamount)
  
VALUES ( 5 , ' 5/30/98 ' , 1929.04 )
INSERT order_emp (employeeID, orderdate, orderamount)
  
VALUES ( 1 , ' 1/03/98 ' , 2039.82 )
INSERT order_emp (employeeID, orderdate, orderamount)
  
VALUES ( 1 , ' 1/22/98 ' , 445.29 )
INSERT order_emp (employeeID, orderdate, orderamount)
  
VALUES ( 4 , ' 4/05/98 ' , 689.39 )
INSERT order_emp (employeeID, orderdate, orderamount)
  
VALUES ( 7 , ' 3/21/98 ' , 1598.23 )
INSERT order_emp (employeeID, orderdate, orderamount)
  
VALUES ( 7 , ' 3/21/98 ' , 445.77 )
INSERT order_emp (employeeID, orderdate, orderamount)
  
VALUES ( 7 , ' 3/22/98 ' , 2178.98 )
GO
SET NOCOUNT OFF
CREATE INDEX emp_order_ind
  
ON order_emp (orderID, employeeID)

D. 使用
FILLFACTOR 選項
下面的示例使用
FILLFACTOR 子句,將其設置爲 100 FILLFACTOR 100 將完全填滿每一頁,只有確定表中的索引值永遠不會更改時,該選項纔有用。

SET NOCOUNT OFF
USE pubs
IF EXISTS ( SELECT name FROM sysindexes
     
WHERE name = ' zip_ind ' )
  
DROP INDEX authors.zip_ind
GO
USE pubs
GO
CREATE NONCLUSTERED INDEX zip_ind
  
ON authors (zip)
  
WITH FILLFACTOR = 100

E. 使用 IGNORE_DUP_KEY
下面的示例爲 emp_pay 表創建唯一聚集索引。如果輸入了重複的鍵,將忽略該
INSERT UPDATE 語句。

SET NOCOUNT ON
USE pubs
IF EXISTS ( SELECT * FROM INFORMATION_SCHEMA.TABLES
     
WHERE TABLE_NAME = ' emp_pay ' )
  
DROP TABLE emp_pay
GO
USE pubs
IF EXISTS ( SELECT name FROM sysindexes
     
WHERE name = ' employeeID_ind ' )
  
DROP INDEX emp_pay.employeeID_ind
GO
USE pubs
GO
CREATE TABLE emp_pay
(
employeeID
int NOT NULL ,
base_pay
money NOT NULL ,
commission
decimal ( 2 , 2 ) NOT NULL
)
INSERT emp_pay
  
VALUES ( 1 , 500 , . 10 )
INSERT emp_pay
  
VALUES ( 2 , 1000 , . 05 )
INSERT emp_pay
  
VALUES ( 3 , 800 , . 07 )
INSERT emp_pay
  
VALUES ( 5 , 1500 , . 03 )
INSERT emp_pay
  
VALUES ( 9 , 750 , . 06 )
GO
SET NOCOUNT OFF
GO
CREATE UNIQUE CLUSTERED INDEX employeeID_ind
  
ON emp_pay(employeeID)
  
WITH IGNORE_DUP_KEY

F. 使用 PAD_INDEX 創建索引
下面的示例爲 authors 表中的作者標識號創建索引。沒有 PAD_INDEX 子句,SQL Server 將創建填充
10 % 的葉級頁,但是葉級之上的頁幾乎被完全填滿。使用 PAD_INDEX 時,中間級頁也填滿 10 %



說明  如果沒有指定 PAD_INDEX,唯一聚集索引的索引頁上至少會出現兩項。


SET NOCOUNT OFF
USE pubs
IF EXISTS ( SELECT name FROM sysindexes
     
WHERE name = ' au_id_ind ' )
  
DROP INDEX authors.au_id_ind
GO
USE pubs
CREATE INDEX au_id_ind
  
ON authors (au_id)
  
WITH PAD_INDEX, FILLFACTOR = 10

G. 爲視圖創建索引
下面的示例將創建一個視圖,併爲該視圖創建索引。然後,引入兩個使用該索引視圖的查詢。

USE Northwind
GO

-- Set the options to support indexed views.
SET NUMERIC_ROUNDABORT OFF
GO
SET ANSI_PADDING,ANSI_WARNINGS,CONCAT_NULL_YIELDS_NULL,ARITHABORT,QUOTED_IDENTIFIER,ANSI_NULLS ON
GO

-- Create view.
CREATE    VIEW V1
WITH    SCHEMABINDING
AS
  
SELECT SUM (UnitPrice * Quantity * ( 1.00 - Discount)) AS Revenue, OrderDate, ProductID, COUNT_BIG( * ) AS COUNT
  
FROM    dbo. [ Order Details ] od, dbo.Orders o
  
WHERE    od.OrderID = o.OrderID
  
GROUP BY    OrderDate, ProductID
GO

-- Create index on the view.
CREATE UNIQUE CLUSTERED INDEX IV1 ON V1 (OrderDate, ProductID)
GO

-- This query will use the above indexed view.
SELECT SUM (UnitPrice * Quantity * ( 1.00 - Discount)) AS Rev, OrderDate, ProductID
FROM    dbo. [ Order Details ] od, dbo.Orders o
WHERE    od.OrderID = o.OrderID AND ProductID in ( 2 , 4 , 25 , 13 , 7 , 89 , 22 , 34 )
  
AND OrderDate >= ' 05/01/1998 '
GROUP BY OrderDate, ProductID
ORDER BY Rev DESC

-- This query will use the above indexed view.
SELECT   OrderDate, SUM (UnitPrice * Quantity * ( 1.00 - Discount)) AS Rev
FROM    dbo. [ Order Details ] od, dbo.Orders o
WHERE    od.OrderID = o.OrderID AND DATEPART (mm,OrderDate) = 3
  
AND DATEPART (yy,OrderDate) = 1998
GROUP BY OrderDate
ORDER BY OrderDate ASC

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