学步园

SQL SERVER 2005中，终于引入了表分区，就是说，当一个表里的数据很多时，可以将其分拆到
多个的表里，大大提高了性能。下面举例子说明之

比如，在C盘下建立如下几个目录
C:/Data2/Primary
C:/Data2/FG1
C:/Data2/FG2
C:/Data2/FG3
C:/Data2/FG4

其中primary存放的是主数据库文件，其他FG1--FG4存放四个单独的文件组，可以见创立数据库
Data Partition DB2，如下

USE [master]
GO
/****** Object:  Database [Data Partition DB]    Script Date: 10/08/2006 23:09:53 ******/
IF  EXISTS (SELECT name FROM sys.databases WHERE name = N'Data Partition DB2')
DROP DATABASE [Data Partition DB2]
GO
CREATE DATABASE [Data Partition DB2]
ON PRIMARY
(NAME='Data Partition DB Primary FG',
FILENAME=
'C:/Data2/Primary/Data Partition DB Primary FG.mdf',
SIZE=5,
MAXSIZE=500,
FILEGROWTH=1 ),
FILEGROUP [Data Partition DB FG1]
(NAME = 'Data Partition DB FG1',
FILENAME =
'C:/Data2/FG1/Data Partition DB FG1.ndf',
SIZE = 5MB,
MAXSIZE=500,
FILEGROWTH=1 ),
FILEGROUP [Data Partition DB FG2]
(NAME = 'Data Partition DB FG2',
FILENAME =
'C:/Data2/FG2/Data Partition DB FG2.ndf',
SIZE = 5MB,
MAXSIZE=500,
FILEGROWTH=1 ),
FILEGROUP [Data Partition DB FG3]
(NAME = 'Data Partition DB FG3',
FILENAME =
'C:/Data2/FG3/Data Partition DB FG3.ndf',
SIZE = 5MB,
MAXSIZE=500,
FILEGROWTH=1 ),
FILEGROUP [Data Partition DB FG4]
(NAME = 'Data Partition DB FG4',
FILENAME =
'C:/Data2/FG4/Data Partition DB FG4.ndf',
SIZE = 5MB,
MAXSIZE=500,
FILEGROWTH=1 )
接下来，我们创建分区表函数，这其实可以理解为一个规则，说明如何以一个规则来将一个表来划分，如下
 use [Data Partition DB2]
GO
CREATE PARTITION FUNCTION [Data Partition Range](int)
AS RANGE LEFT FOR VALUES (100,200,300)
其中分区函数的名称是Data Partition Range,后面的类型（int)表明接下来用来分区的那个字段的类型是INT类型，

而VALUES (100,200,300)表明，将把表分为4个区了，是从负数到100，100-200，200-300，大于300。

接下来，我们要创建分区架构，即将分区函数应用到我们分好的四个文件组里面去

USE [Data Partition DB2]
go
CREATE PARTITION SCHEME [Data Partition Scheme]
AS PARTITION [Data Partition Range]
TO ([Data Partition DB FG1], [Data Partition DB FG2], [Data Partition DB FG3],[Data Partition DB FG4]);

再创建表的结构
USE [Data Partition DB2]

go
CREATE TABLE MyTable
(ID INT NOT NULL, Date DATETIME, Cost money)    
   ON [Data Partition Scheme] (ID);

这里注意，ON [Data Partition Scheme] (ID);表明，划分时以ID的大小作为划分的根据，ON后要跟分区架购的名称

最后，我们可以填充数据了

USE [Data Partition DB2]
go
declare @count int
set @count =-25
while @count <=100
begin
insert into MyTable select @count,getdate(),100.00
set @count=@count+1
end
set @count =101
while @count <=200
begin
insert into MyTable select @count,getdate(),200.00
set @count=@count+1
end
set @count =201
while @count <=300
begin
insert into MyTable select @count,getdate(),300.00
set @count=@count+1
end
set @count =301
while @count <=400
begin
insert into MyTable select @count,getdate(),400.00
set @count=@count+1
end
set @count =401
while @count <=800
begin
insert into MyTable select @count,getdate(),500.00
set @count=@count+1
end

最后，我们可以查询下，插入的这些数据，是否真的被划分到四个不同的文件组里的表分区了，可以这样看
SELECT *, $PARTITION.[Data Partition Range](ID)
 FROM MyTable