SQLSERVER2008中CTE的Split与CLR的性能比较

2016-04-04数据库

我们新建一个DataBase project，然后建立一个UserDefinedFunctions,Code像这样:

代码如下:

 
1: /// <summary> 
/// SQLs the array. 
/// </summary> 
/// <param name="str">The STR.</param> 
/// <param name="delimiter">The delimiter.</param> 
/// <returns></returns> 
/// 1/8/2010 2:41 PM author: v-pliu 
[SqlFunction(Name = "CLR_Split", 
FillRowMethodName = "FillRow", 
TableDefinition = "id nvarchar(10)")] 
public static IEnumerable SqlArray(SqlString str, SqlChars delimiter) 
{ 
if (delimiter.Length == 0) 
return new string[1] { str.Value }; 
return str.Value.Split(delimiter[0]); 
} 
/// <summary> 
/// Fills the row. 
/// </summary> 
/// <param name="row">The row.</param> 
/// <param name="str">The STR.</param> 
/// 1/8/2010 2:41 PM author: v-pliu 
public static void FillRow(object row, out SqlString str) 
{ 
str = new SqlString((string)row); 
} 

然后Bulid,Deploy一切OK后，在SSMS中执行以下测试T-sql:

代码如下:

 
DECLARE @array VARCHAR(max) 
SET @array = '39,15,93,68,64,43,90,58,39,9,26,26,89,47,91,57,98,16,55,9,63,29,69,16,41,76,34,60,68,64,61,53,32,30,11,72,57,63,36,43,22,14,60,38,24,5,66,26,26,21,22,99,55,18,7,10,46,76,27,88,9,29,89,75,48,72,94,59,35,19,0,35,79,11,87,49,68,30,91,35,9,7,34,47,41,61,98,13,22,1,26,80,35,48,34,92,24,85,90,51' SELECT id FROM dbo.CLR_Split(@array,',') 

我们来看它的Client Statistic:

CLRSplit

接着我们执行测试T-sql使用相同的array:

代码如下:

 
DECLARE @array VARCHAR(max) 
SET @array = '39,15,93,68,64,43,90,58,39,9,26,26,89,47,91,57,98,16,55,9,63,29,69,16,41,76,34,60,68,64,61,53,32,30,11,72,57,63,36,43,22,14,60,38,24,5,66,26,26,21,22,99,55,18,7,10,46,76,27,88,9,29,89,75,48,72,94,59,35,19,0,35,79,11,87,49,68,30,91,35,9,7,34,47,41,61,98,13,22,1,26,80,35,48,34,92,24,85,90,51' 
SELECT item FROM strToTable(@array,',') 

CTE实现的Split function的Client statistic:

CTESplit

通过对比，你可以发现CLR的performance略高于CTE方式，原因在于CLR方式有Cache功能，并且把一个复杂的运算放到程序里比DataBase里更加高效。

您还可以参考：
Split string in SQL Server 2005+ CLR vs. T-SQL
Author:Petter Liu

The End

liunx mysql root账户提示：Your password has expired. To log in yo

liunx mysql root账户提示：Your password has expired. To log in you must change it using a client that supports expired passwords，要怎么操作呢？ 1、修改 /etc/my.cnf，在 [mysqld] 小节下添加一行：skip-grant-tables=1 这一行配置让 mysqld 启动...

2024-12-24 数据库

149