原贴：http://topic.csdn.net/u/20100412/11/a4ea520e-7dd0-44d2-98bb-9f62f0ed6160.html?21233
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-- Author : htl258(Tony)
-- Date : 2010-04-14 06:02:36
-- Version:Microsoft SQL Server 2008 (RTM) - 10.0.1600.22 (Intel X86)
-- Jul 9 2008 14:43:34
-- Copyright (c) 1988-2008 Microsoft Corporation
-- Developer Edition on Windows NT 5.1 <X86> (Build 2600: Service Pack 2)
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--> 生成测试数据表:tb
IF NOT OBJECT_ID('[tb]') IS NULL
DROP TABLE [tb]
GO
CREATE TABLE [tb]([callno] INT,[calledno] INT,[groupid] INT)
INSERT [tb]
SELECT 111,1000,1 UNION ALL
SELECT 111,2000,1 UNION ALL
SELECT 222,1000,2 UNION ALL
SELECT 222,4000,2 UNION ALL
SELECT 333,5000,3 UNION ALL
SELECT 333,6000,3 UNION ALL
SELECT 444,4000,4 UNION ALL
SELECT 444,1,4 UNION ALL
SELECT 444,2,4 UNION ALL
SELECT 555,55,5 UNION ALL
SELECT 555,5000,5 UNION ALL
--
SELECT 666,8,6 UNION ALL
SELECT 666,88,6 UNION ALL
SELECT 666,888,6 UNION ALL
SELECT 777,9,7 UNION ALL
SELECT 777,99,7 UNION ALL
SELECT 777,999,7 UNION ALL
SELECT 888,44,8 UNION ALL
SELECT 888,444,8 UNION ALL
SELECT 999,66,9 UNION ALL
SELECT 999,666,9 UNION ALL
SELECT 999,44,9 UNION ALL
SELECT 999,99,9 UNION ALL
SELECT 9999,44,10 UNION ALL
SELECT 9999,8,10 UNION ALL
--
SELECT 1,100,100 UNION ALL
SELECT 1,200,100 UNION ALL
SELECT 2,200,200 UNION ALL
SELECT 2,300,200 UNION ALL
SELECT 3,300,300 UNION ALL
SELECT 3,400,300 UNION ALL
SELECT 4,400,400 UNION ALL
SELECT 4,500,400 UNION ALL
SELECT 5,500,500 UNION ALL
SELECT 5,600,500 UNION ALL
SELECT 6,600,600
GO
--SELECT * from [tb]
-->SQL查询如下:
DECLARE @CALLNO INT,@CALLEDNO
1. /*+ALL_ROWS*/
表明对语句块选择基于开销的优化方法,并获得最佳吞吐量,使资源消耗最小化.
例如:
SELECT /*+ALL+_ROWS*/ EMP_NO,EMP_NAM,DAT_IN from BSEMPMS WHERE EMP_NO='CCBZZP';
2. /*+FIRST_ROWS*/
表明对语句块选择基于开销的优化方法,并获得最佳响应时 ......
