按照网上的资料进行的百万级循环插入的效率分析循环插入数据库90万条数据的代码

一循环插入数据库90万条数据的代码如下

TRUNCATE TABLE dbo.People

GO

---以下两句用于清楚sqlserver的数据跟缓存线上的服务器不建议使用

DBCC DROPCLEANBUFFERS

DBCC FREEPROCCACHE

SET STATISTICS IO ON;

SET STATISTICS TIME ON;

GO

DECLARE @d Datetime

SET @d=GETDATE();

DECLARE @i INT =1

WHILE @i<900000

BEGIN

INSERT INTO dbo.People

(name, sex, age)

SELECT 'preson'+cast(@i as varchar(10)),

CASE WHEN @i%2=0 THEN 0

WHEN @i%2=1 THEN 1

END

,

CAST(RAND()*10 AS INT)%10+(@i%26)

SET @i=@i+1

END

SELECT [语句执行花费时间(毫秒)]=DATEDIFF(ms,@d,GETDATE())

SET STATISTICS IO OFF;

SET STATISTICS TIME OFF;

GO

1未使用set nocount on 和 TRANSACTION

使用的时间为614280秒；

2使用了set nocount on 和 TRANSACTION

TRUNCATE TABLE dbo.People

GO

---以下两句用于清楚sqlserver的数据跟缓存线上的服务器不建议使用

DBCC DROPCLEANBUFFERS

DBCC FREEPROCCACHE

SET STATISTICS IO ON;

SET STATISTICS TIME ON;

GO

DECLARE @d Datetime

SET @d=GETDATE();

SET NOCOUNT ON

DECLARE @i INT =1

BEGIN TRANSACTION

WHILE @i<900000

BEGIN

INSERT INTO dbo.People

(name, sex, age)

SELECT 'preson'+cast(@i as varchar(10)),

CASE WHEN @i%2=0 THEN 0

WHEN @i%2=1 THEN 1

END

,

CAST(RAND()*10 AS INT)%10+(@i%26)

SET @i=@i+1

END

COMMIT

SELECT [语句执行花费时间(毫秒)]=DATEDIFF(ms,@d,GETDATE())

SET STATISTICS IO OFF;

SET STATISTICS TIME OFF;

GO

使用的时间为267566秒；

3.使用了with as

代码如下

TRUNCATE TABLE dbo.People

GO

---以下两句用于清楚sqlserver的数据跟缓存线上的服务器不建议使用

DBCC DROPCLEANBUFFERS

DBCC FREEPROCCACHE

SET STATISTICS IO ON;

SET STATISTICS TIME ON;

GO

DECLARE @d Datetime

SET @d=GETDATE();

/**用with as */

WITH Seq(id,name,sex,age) AS

(

SELECT 1,

'preson'+cast(1 AS VARCHAR(10)),

1,

CAST(RAND()*10 AS INT)%10

UNION ALL

SELECT id+1,

'preson'+cast(id+1 as varchar(10)),

CASE WHEN id%2=0 THEN 0

WHEN id%2=1 THEN 1

END

,

CAST(RAND()*10 AS INT)%10+(id%26)

FROM Seq

WHERE id<900000

)

INSERT INTO dbo.People

(name, sex, age)

SELECT name,

sex,

age

FROM Seq

OPTION (MAXRECURSION 0)

SELECT [语句执行花费时间(毫秒)]=DATEDIFF(ms,@d,GETDATE())

SET STATISTICS IO OFF;

SET STATISTICS TIME OFF;

GO

使用时间为28430秒

4.总结

A:仅仅是while循环运行了614280s,

B:set nocount on 和TRANSACTION运行了267566s,

C:使用了with as 递归插入 运行了28430s。

A/B=2.3

A/C=21938

使用with as 的性能是最简单循环插入的2万多倍