现在基本所有数据库都存在表分区的概念,但MSSQL表分区一些细节又不一样,我现在也是有一定的了解,因此本篇文章不做很细的原理性质的讲解,主要讲一下MSSQL表分区的创建过程。
首先创建新的文件,分别放到我本机的D:SPPartition文件夹下的FirstPart,SecondPart,ThirdPart文件夹,新建3个文件文件分别对应3个文件组,以我本机中存在的数据库CenterMy为例子,它现在有个表TestSP,这是一个用户表,现在测试数据只有1000多条数据,创建代码如下:
代码如下 | 复制代码 |
ALTER DATABASE CenterMy ADD FILEGROUP FGSP1 GO ALTER DATABASE CenterMy ADD FILE ( NAME = 'SPTestLevel1', FILENAME = 'D:SPPartitionFirstPartSPTestLevel1.ndf', SIZE = 5120 KB, MAXSIZE = UNLIMITED, FILEGROWTH = 5120 KB ) TO FILEGROUP FGSP1 GO |
代码如下 | 复制代码 |
ALTER DATABASE CenterMy ADD FILEGROUP FGSP2 GO ALTER DATABASE CenterMy ADD FILE ( NAME = 'SPTestLevel2', FILENAME = 'D:SPPartitionSecondPartSPTestLevel2.ndf', SIZE = 5120 KB, MAXSIZE = UNLIMITED, FILEGROWTH = 5120 KB ) TO FILEGROUP FGSP2 GO |
代码如下 | 复制代码 |
ALTER DATABASE CenterMy ADD FILEGROUP FGSP3 GO ALTER DATABASE CenterMy ADD FILE ( NAME = 'SPTestLevel3', FILENAME = 'D:SPPartitionThirdPartSPTestLevel3.ndf', SIZE = 5120 KB, MAXSIZE = UNLIMITED, FILEGROWTH = 5120 KB ) TO FILEGROUP FGSP3 GO |
查询当前数据库CenterMy的分组:
代码如下 | 复制代码 |
SELECT * FROM sys.filegrou |
查看当前数据文件:
代码如下 | 复制代码 |
SELECT * FROM sys.database_files |
下面创建分区函数,它将为分区中数据分布制定标准。
代码如下 | 复制代码 |
CREATE PARTITION FUNCTION TestSPFunction (INT) AS RANGE RIGHT FOR VALUES ( 500, 1000,1300) GO |
然后创建分区方案,它将创建的分区函数映射到文件组,文件组对应磁盘上的物理数据库文件。
代码如下 | 复制代码 |
CREATE PARTITION SCHEME TestSPScheme AS PARTITION TestSPFunction TO ([PRIMARY], FGSP1, FGSP2,FGSP3 ) GO |
然后把表链接到分区方案,这里使用SPNO主键作为分区列。
ALTER TABLE TestSP add CONSTRAINT [PK_SPNO] PRIMARY KEY CLUSTERED (SPNo)
ON TestSPScheme(SPNo)
通过上面的操作,表分区就创建好了,并且数据自动放到相应的分区中了,下面我们查询下各个分区对应的数据量。
*
FROM sys.partitions
WHERE OBJECT_NAME(OBJECT_ID)='TestSP'
可以看到主分区有467条记录,partion_number的1,2,3,4分别对应不同文件组对应的row数据条数。
最后查询表的时候,可以在完全不知道表分区的情况下查询,我们查看下数据对应的所在分区:
SELECT *, $PARTITION.TestSPFunction(SPNo)
FROM TestSP
发现SPNO为500的正好在第二个分区了,证明我们创建表分区成功了!
上面只是简单描述了下表分区的过程,MSSQL2008还新增了可视化界面来添加表分区,如图:
本文主要是展现了分区的过程,对于实际项目中,是否需要分区,怎么分区,分区部署到什么磁盘上,分区后索引创建以及是否能达到优化的效果,还需要再根据实际情况更多的考虑,

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