CREATE INDEX
为给定表或视图创建索引。

只有表或视图的所有者才能为表创建索引。表或视图的所有者可以随时创建索引，无论表中是否有数据。可以通过指定限定的数据库名称，为另一个数据库中的表或视图创建索引。

语法
CREATE [ UNIQUE ] [ CLUSTERED | NONCLUSTERED ] INDEX index_name
  ON { table | view } ( column [ ASC | DESC ] [ ,...n ] )  
[ WITH < index_option > [ ,...n] ]  
[ ON filegroup ]

< index_option > ::=  
  { PAD_INDEX |
  FILLFACTOR = fillfactor |
  IGNORE_DUP_KEY |
  DROP_EXISTING |
  STATISTICS_NORECOMPUTE |
  SORT_IN_TEMPDB   
}

A. 使用简单索引
下面的示例为 authors 表的 au_id 列创建索引。

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
下面的示例为 emp_pay 表的 employeeID 列创建索引，并且强制唯一性。因为指定了 CLUSTERED 子句，所以该索引将对磁盘上的数据进行物理排序。  

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. 使用简单组合索引
下面的示例为 order_emp 表的 orderID 列和 employeeID 列创建索引。

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 选项
下面的示例使用 FILLFACTOR 子句，将其设置为 100。FILLFACTOR 为 100 将完全填满每一页，只有确定表中的索引值永远不会更改时，该选项才有用。

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
下面的示例为 emp_pay 表创建唯一聚集索引。如果输入了重复的键，将忽略该 INSERT 或 UPDATE 语句。

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 创建索引
下面的示例为 authors 表中的作者标识号创建索引。没有 PAD_INDEX 子句，SQL Server 将创建填充 10% 的叶级页，但是叶级之上的页几乎被完全填满。使用 PAD_INDEX 时，中间级页也填满 10%。



说明 如果没有指定 PAD_INDEX，唯一聚集索引的索引页上至少会出现两项。


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. 为视图创建索引
下面的示例将创建一个视图，并为该视图创建索引。然后，引入两个使用该索引视图的查询。

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