SQL Server高級進階之表磁區洗掉

一、引言

洗掉磁區又稱為合并磁區，簡單地講就是將多個磁區的資料進行合并，現以表Sales.SalesOrderHeader作為示例，演示如何進行表磁區洗掉，

重要的事情說三遍：備份資料庫！備份資料庫！備份資料庫！

二、演示

2.1、資料查詢

1）查看磁區元資料

SELECT * FROM SYS.PARTITION_FUNCTIONS       --磁區函式
SELECT * FROM SYS.PARTITION_RANGE_VALUES    --磁區方案

2）統計每個磁區的資料量

SELECT $PARTITION.SalesOrderHeader_OrderDate(OrderDate) AS NUMBER,COUNT(1) AS COUNT
FROM [Sales].[SalesOrderHeader]
GROUP BY $PARTITION.SalesOrderHeader_OrderDate(OrderDate)

磁區表中有資料時，是不能夠洗掉磁區方案和磁區函式的，只能將資料先移到其它表中，再洗掉，

2.2、洗掉實操

2.2.1、合并原表磁區

ALTER PARTITION FUNCTION SalesOrderHeader_OrderDate() MERGE RANGE('2011-01-01 00:00:00.000')
ALTER PARTITION FUNCTION SalesOrderHeader_OrderDate() MERGE RANGE('2012-01-01 00:00:00.000')
ALTER PARTITION FUNCTION SalesOrderHeader_OrderDate() MERGE RANGE('2013-01-01 00:00:00.000')
ALTER PARTITION FUNCTION SalesOrderHeader_OrderDate() MERGE RANGE('2014-01-01 00:00:00.000')

2.2.2、備份原表所有索引的創建腳本

ALTER TABLE [Sales].[SalesOrderHeader] ADD  CONSTRAINT [PK_SalesOrderHeader_SalesOrderID] PRIMARY KEY NONCLUSTERED 
(
    [SalesOrderID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]

2.2.3、洗掉原表所有索引

ALTER TABLE [Sales].[SalesOrderHeader] DROP CONSTRAINT [PK_SalesOrderHeader_SalesOrderID]

2.2.4、創建臨時表

CREATE TABLE [Sales].[SalesOrderHeader_Temp](
    [SalesOrderID] [INT] IDENTITY(1,1) NOT FOR REPLICATION NOT NULL,
    [RevisionNumber] [TINYINT] NOT NULL,
    [OrderDate] [DATETIME] NOT NULL,
    [DueDate] [DATETIME] NOT NULL,
    [ShipDate] [DATETIME] NULL,
    [Status] [TINYINT] NOT NULL,
    [OnlineOrderFlag] [dbo].[Flag] NOT NULL,
    [SalesOrderNumber]  AS (ISNULL(N'SO'+CONVERT([NVARCHAR](23),[SalesOrderID]),N'*** ERROR ***')),
    [PurchaseOrderNumber] [dbo].[OrderNumber] NULL,
    [AccountNumber] [dbo].[AccountNumber] NULL,
    [CustomerID] [INT] NOT NULL,
    [SalesPersonID] [INT] NULL,
    [TerritoryID] [INT] NULL,
    [BillToAddressID] [INT] NOT NULL,
    [ShipToAddressID] [INT] NOT NULL,
    [ShipMethodID] [INT] NOT NULL,
    [CreditCardID] [INT] NULL,
    [CreditCardApprovalCode] [VARCHAR](15) NULL,
    [CurrencyRateID] [INT] NULL,
    [SubTotal] [MONEY] NOT NULL,
    [TaxAmt] [MONEY] NOT NULL,
    [Freight] [MONEY] NOT NULL,
    [TotalDue]  AS (ISNULL(([SubTotal]+[TaxAmt])+[Freight],(0))),
    [Comment] [NVARCHAR](128) NULL,
    [rowguid] [UNIQUEIDENTIFIER] ROWGUIDCOL  NOT NULL,
    [ModifiedDate] [DATETIME] NOT NULL
)

2.2.5、更改原表資料空間型別

1）對著原表Sales.SalesOrderHeader點擊"右鍵"->"設計"，

2）點擊選單欄"視圖"->"屬性視窗"，

3）將資料空間型別更改為"檔案組"，常規資料空間規范默認為"PRIMARY"，

2.2.6、移動原表磁區資料到臨時表

ALTER TABLE [Sales].[SalesOrderHeader] SWITCH PARTITION 1 TO [Sales].[SalesOrderHeader_Temp] PARTITION 1

2.2.7、創建原表所有索引到臨時表

ALTER TABLE [Sales].[SalesOrderHeader_Temp] ADD  CONSTRAINT [PK_SalesOrderHeader_SalesOrderID] PRIMARY KEY NONCLUSTERED 
(
    [SalesOrderID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]

2.2.8、洗掉原表

DROP TABLE Sales.SalesOrderHeader

2.2.9、洗掉磁區方案和磁區函式

DROP PARTITION SCHEME SalesOrderHeader_OrderDate
DROP PARTITION FUNCTION SalesOrderHeader_OrderDate

2.2.10重命名表名

EXEC SP_RENAME '[Sales].[SalesOrderHeader_Temp]','SalesOrderHeader'

標籤：SQL Server

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