以下是如何为RANGE RIGHT 函数创建增量每月分区的示例,包括测试数据。
CREATE DATABASE Test;
GO
USE Test
GO
--main table partition function (before start of next month)
CREATE PARTITION FUNCTION PF_Monthly(datetime2(0))
AS RANGE RIGHT FOR VALUES (
'2015-01-01T00:00:00'
, '2015-02-01T00:00:00'
, '2015-03-01T00:00:00'
, '2015-04-01T00:00:00'
, '2015-05-01T00:00:00'
, '2015-06-01T00:00:00'
, '2015-07-01T00:00:00'
, '2015-08-01T00:00:00'
, '2015-09-01T00:00:00'
, '2015-10-01T00:00:00'
, '2015-11-01T00:00:00'
, '2015-12-01T00:00:00'
, '2016-01-01T00:00:00' --future empty partition
)
GO
--main table partition scheme
CREATE PARTITION SCHEME PS_Monthly
AS PARTITION PF_Monthly
ALL TO ( [PRIMARY] );
GO
--main partitioned table
CREATE TABLE dbo.MontylyPartitionedTable(
PartitioningColumn datetime2(0)
, OtherKeyColumn int NOT NULL
, OtherData int NULL
, CONSTRAINT PK_MontylyPartitionedTable PRIMARY KEY
CLUSTERED (PartitioningColumn, OtherKeyColumn)
ON PS_Monthly(PartitioningColumn)
) ON PS_Monthly(PartitioningColumn);
GO
---load 12M rows test data
WITH
t4 AS (SELECT n FROM (VALUES(0),(0),(0),(0)) t(n))
,t256 AS (SELECT 0 AS n FROM t4 AS a CROSS JOIN t4 AS b CROSS JOIN t4 AS c CROSS JOIN t4 AS d)
,t16M AS (SELECT ROW_NUMBER() OVER (ORDER BY (a.n)) - 1 AS num FROM t256 AS a CROSS JOIN t256 AS b CROSS JOIN t256 AS c)
INSERT INTO dbo.MontylyPartitionedTable WITH (TABLOCKX) (PartitioningColumn, OtherKeyColumn, OtherData)
SELECT DATEADD(month, num/1000000, '20150101'), num, num
FROM t16M
WHERE num < 12000000;
GO
CREATE PROCEDURE dbo.CreateMonthlyPartition
@NewMonthStartDate datetime2(0) --partition boundary to create
/*
*/
AS
SET XACT_ABORT ON;
BEGIN TRY
BEGIN TRAN;
--acquire exclusive lock on main table to prevent deadlocking during partition maintenance
DECLARE @result int = (SELECT TOP (0) 1 FROM dbo.MontylyPartitionedTable WITH (TABLOCKX));
--add new partition for future data
ALTER PARTITION SCHEME PS_Monthly
NEXT USED [PRIMARY];
ALTER PARTITION FUNCTION PF_Monthly()
SPLIT RANGE (@NewMonthStartDate);
--this will release the exclusve table lock but the data in the staging table temporarily unavailable
COMMIT;
END TRY
BEGIN CATCH
IF @@TRANCOUNT > 0 ROLLBACK;
THROW;
END CATCH;
GO
--schedule this before the start of each new month to create a new monthly partition 2 months in advance
SELECT DATEADD(day, 1, DATEADD(month, 1, EOMONTH(GETDATE())));
DECLARE @NewMonthStartDate datetime2(0) = DATEADD(day, 1, DATEADD(month, 1, EOMONTH(GETDATE())));
EXEC dbo.CreateMonthlyPartition @NewMonthStartDate;
GO