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SQLSERVER2008中CTE的Split與CLR的性能比較_Mssql數(shù)據(jù)庫教程

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推薦：SQL SERVER 2008 CTE生成結(jié)點的FullPath
SQL SERVER 2008 使用CTE是經(jīng)常的事兒，有時我們想存儲一些冗余數(shù)據(jù)，像每個結(jié)點的FullPath。

我們新建一個DataBase project，然后建立一個UserDefinedFunctions,Code像這樣:
復(fù)制代碼 代碼如下:hl5o.cn

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中執(zhí)行以下測試T-sql:
復(fù)制代碼 代碼如下:hl5o.cn

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,',')

我們來看它的Client Statistic:

接著我們執(zhí)行測試T-sql使用相同的array:

復(fù)制代碼 代碼如下:hl5o.cn

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實現(xiàn)的Split function的Client statistic:

通過對比，你可以發(fā)現(xiàn)CLR的performance略高于CTE方式，原因在于CLR方式有Cache功能，并且把一個復(fù)雜的運算放到程序里比DataBase里更加高效。

您還可以參考：

Author:Petter Liu

分享：Sql server 2008 express遠程登錄實例設(shè)置 圖文教程
Sql server 2008 express遠程登錄實例設(shè)置 圖文教程，需要的朋友可以參考下。

來源：模板無憂//所屬分類：Mssql數(shù)據(jù)庫教程/更新時間：2013-04-23
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