【推荐】[SQL优化工具]Quest.Central.For.Databases——SQL Tuning for SQL Server

随着企业数据库的急剧膨胀和日益复杂，DBA为保证数据库性能所付出的努力与日俱增，手工或使用多种无法集成的管理工具，都会给日常管理和维护带来不必要的困难。 Quest Central for Databases 是一种集成化、图形化、跨平台的数据库管理解决方案，可以管理异构环境下的 Oracle、DB2 和 SQL server 数据库。Quest Central for Databases 消除了企业IT人员管理多种数据库时面临的技术障碍，提高了IT人员工作效率，改善了数据库性能和数据库应用的可用性。为灵活满足用户的不同需求，Quest Central for Databases 采用了模块化产品架构。

该产品包括下列功能模块:

1.         数据库管理（DBA）

2.         数据库监控（Monitoring Pack）

3.         数据库诊断 (Spotlight Diagnostics)

4.         数据库分析 (Database Analysis)

5.         SQL优化 (SQL Tuning)

6.         空间管理 (Space Management)

7.         压力测试 (Load Generator)

8.         数据生成 (Data Generator)

9.         PL/SQL 开发 (TOAD)

10.     专家建议 (Knowledge Expert) 

今天主要介绍其中的SQL优化工具—— SQL Tuning for SQL Server

一、SQL Tuning for SQL Server简介

SQL语句的优化对发挥数据库的最佳性能非常关键。然而不幸的是，应用优化通常由于时间和资源的因素而被忽略。SQL Tuning (SQL优化)模块可以对比和评测特定应用中SQL语句的运行性能，提出智能化的优化建议，帮助用户改善应用的响应时间。SQL优化模块具有非介入式SQL采集、自动优化和专家建议等功能，全面改善SQL优化工作。

       二、SQL Tuning for SQL Server的使用

      1、打开Quest Database Management Solutions弹出窗口如图1所示       
      
                                                                          图1  

    2、在红色标记处打开SQL Tuning 优化SQL    

  （1）建立连接。

    在Quest Central主界面上的“Database”树上选择“SQL Server”，然后在下方出现的“Tools”框中选择“SQL Tuning”选项，打开“Lanch SQL Tuning for SQL Server Connections”对话框（图2、图3）。我们在这里建立数据库服务器的连接，以后的分析工作都会在它上面完成。 

                   

                                         图2 “建立连接”对话框 

                           

                                         图3

     双击“New Connection”图标，在弹出窗口中输入数据库的信息，单击“OK”，然后单击“Connect”即可。

   （2）分析原始SQL语句 ，在单击“Connect”后将弹出一个新窗口，如图4 

             

                                                                  图4

     在打开窗口的“Oriangal SQL”文本框内输入需要分析的原始SQL语句，红色标记处选择对应的数据库名，SQL语句代码如下：   

原始SQL语句

SELECT  dbo.Person_BasicInfo. * , dbo.Graduater_GraduaterRegist.RegistNO  AS  RegistNO, 
      dbo.Graduater_GraduaterRegist.RegistTime  AS  BaoDaoTime, 
      dbo.Graduater_GraduaterRegist.RegistMan  AS  RegistMan, 
      dbo.Graduater_Business.ComeFrom  AS  ComeFrom, 
      dbo.Graduater_Business.Code  AS  Code, dbo.Graduater_Business.Status  AS  Status, 
      dbo.Graduater_Business.ApproveResult  AS  ApproveResult, 
      dbo.Graduater_Business.NewCorp  AS  NewCorp, 
      dbo.Graduater_Business.CommendNumber  AS  CommendNumber, 
      dbo.Graduater_Business.EmployStatus  AS  EmployStatus, 
      dbo.Graduater_Business.NewCommendTime  AS  NewCommendTime, 
      dbo.Graduater_Business.GetSource  AS  GetSource, 
      dbo.Graduater_Business.EmployTime  AS  EmployTime, 
      dbo.Graduater_Business.Job  AS  Job, dbo.Graduater_Business.FillMan  AS  FillMan, 
      dbo.Graduater_Business.FillTime  AS  FillTime, 
      dbo.Graduater_Business.IsCommendOK  AS  IsCommendOK, 
      dbo.Graduater_Business.ApproveUser  AS  ApproveUser, 
      dbo.Graduater_Business.ApproveTime  AS  ApproveTime, 
      dbo.Graduater_Business.RegistTime  AS  RegistTime, 
      dbo.Graduater_Business.EmployCorp  AS  EmployCorp, 
      dbo.Graduater_Business.JobRemark  AS  JobRemark, 
       CASE   WHEN  dbo.Graduater_Business.ComeFrom  =   ' WS '   THEN   ' 网上登记 '   WHEN  dbo.Graduater_Business.ComeFrom
        =   ' HP '   THEN   ' 华普大厦 '   WHEN  dbo.Graduater_Business.ComeFrom  =   ' JD '   THEN   ' 精典大厦 '
        WHEN  dbo.Graduater_Business.ComeFrom  =   ' MC '   THEN   ' 赛马场 '   WHEN  ComeFrom  =
        ' ZX '   THEN   ' 高指中心 '   END   AS  ComeFromName, 
      dbo.Person_Contact.Address  AS  Address, dbo.Person_Contact.Zip  AS  Zip, 
      dbo.Person_Contact.Telephone  AS  Telephone, dbo.Person_Contact.Mobile  AS  Mobile, 
      dbo.Person_Contact.Email  AS  Email, dbo.Person_Contact.IM  AS  IM, 
      dbo.Person_Skill.ForeignLanguage  AS  ForeignLanguage, 
      dbo.Person_Skill.ForeignLanguageLevel  AS  ForeignLanguageLevel, 
      dbo.Person_Skill.CantoneseLevel  AS  CantoneseLevel, 
      dbo.Person_Skill.MandarinLevel  AS  MandarinLevel, 
      dbo.Person_Skill.Language  AS  Language, 
      dbo.Person_Skill.TechnicalTitle  AS  TechnicalTitle, 
      dbo.Person_Skill.ComputerLevel  AS  ComputerLevel, 
      dbo.Person_EmployPurpose.JobType  AS  JobType, 
      dbo.Person_EmployPurpose.Vocation  AS  Vocation, 
      dbo.Person_EmployPurpose.JobPlace  AS  JobPlace, 
      dbo.Person_EmployPurpose.Salary  AS  Salary, 
      dbo.Person_EmployPurpose.OnJobDate  AS  OnJobDate, 
      dbo.Person_EmployPurpose.CorpType  AS  CorpType, 
      dbo.Person_EmployPurpose.Job  AS  RequireJob,  YEAR ( GETDATE ()) 
       -   YEAR (dbo.Person_BasicInfo.Birthday)  AS  Age, 
      dbo.Graduater_Business.EmployType  AS  EmployType, 
      dbo.Graduater_Business.EmployTypeCode  AS  EmployTypeCode, 
      dbo.Graduater_Business.EmployCorpType  AS  EmployCorpType, 
       CASE   WHEN  dbo.Graduater_Business.PrintStatus  =   ' 已打印 '   THEN   ' 已打印 '   ELSE   ' 未打印 '
        END   AS  PrintStatus, dbo.Graduater_Business.PrintTime  AS  PrintTime, 
       CASE   WHEN  dbo.Graduater_Business.EmployStatus  =   ' 是 '   THEN   ' 已就业 '   ELSE   ' 未就业 '
        END   AS  EmployStatusView
FROM  dbo.Person_BasicInfo  INNER   JOIN
      dbo.Graduater_Business  ON  
      dbo.Person_BasicInfo.PersonID  =  dbo.Graduater_Business.PersonID  LEFT   OUTER   JOIN
      dbo.Graduater_GraduaterRegist  ON  
      dbo.Graduater_Business.GradBusinessID  =  dbo.Graduater_GraduaterRegist.GraduaterGUID
        INNER   JOIN
      dbo.Person_Contact  ON  
      dbo.Person_BasicInfo.PersonID  =  dbo.Person_Contact.PersonID  INNER   JOIN
      dbo.Person_Skill  ON  
      dbo.Person_BasicInfo.PersonID  =  dbo.Person_Skill.PersonID  INNER   JOIN
      dbo.Person_EmployPurpose  ON  
      dbo.Person_BasicInfo.PersonID  =  dbo.Person_EmployPurpose.PersonID

   然后点击工具栏上的“Execute”按钮，执行原始的SQL语句，SQL Tuning会自动分析SQL的执行计划，并把分析结果显示到界面上（图5）。                    
                       
 　　　　　　　　　　　　　　　　　　　　　　图5 分析原始SQL语句

   （3）优化SQL。

   现在我们点击工具栏上的“Optimize Statement”按钮,让SQL Tuning开始优化SQL，完成后，可以看到SQL Tuning产生了19条与原始SQL等价的优化方案（图6）。 

          

                                                        图6 SQL优化方案 

 （4）获得最优SQL。

     接下来，我们来执行上面产生的优化方案，以选出性能最佳的等效SQL语句。在列表中选择需要执行的优化方案(默认已全部选中)，然后点击工具栏上的“Execute”按钮旁边的下拉菜单，选择“Execute Selected”。等到所有SQL运行完成后,点击界面左方的“Tuning Resolution”按钮，
可以看到最优的SQL已经出来啦，运行时间竟然可以提高21%！（图7） 

           

                                            图7 “Tuning Resolution”界面 

     最优的SQL语句如下：  

优化后的SQL语句

SELECT  dbo.Person_BasicInfo. * , 
       dbo.Graduater_GraduaterRegist.RegistNO  AS  RegistNO, 
       dbo.Graduater_GraduaterRegist.RegistTime  AS  BaoDaoTime, 
       dbo.Graduater_GraduaterRegist.RegistMan  AS  RegistMan, 
       dbo.Graduater_Business.ComeFrom  AS  ComeFrom, 
       dbo.Graduater_Business.Code  AS  Code, 
       dbo.Graduater_Business.Status  AS  Status, 
       dbo.Graduater_Business.ApproveResult  AS  ApproveResult, 
       dbo.Graduater_Business.NewCorp  AS  NewCorp, 
       dbo.Graduater_Business.CommendNumber  AS  CommendNumber, 
       dbo.Graduater_Business.EmployStatus  AS  EmployStatus, 
       dbo.Graduater_Business.NewCommendTime  AS  NewCommendTime, 
       dbo.Graduater_Business.GetSource  AS  GetSource, 
       dbo.Graduater_Business.EmployTime  AS  EmployTime, 
       dbo.Graduater_Business.Job  AS  Job, 
       dbo.Graduater_Business.FillMan  AS  FillMan, 
       dbo.Graduater_Business.FillTime  AS  FillTime, 
       dbo.Graduater_Business.IsCommendOK  AS  IsCommendOK, 
       dbo.Graduater_Business.ApproveUser  AS  ApproveUser, 
       dbo.Graduater_Business.ApproveTime  AS  ApproveTime, 
       dbo.Graduater_Business.RegistTime  AS  RegistTime, 
       dbo.Graduater_Business.EmployCorp  AS  EmployCorp, 
       dbo.Graduater_Business.JobRemark  AS  JobRemark, 
        CASE   WHEN  dbo.Graduater_Business.ComeFrom  =   ' WS '   THEN   ' 网上登记 '  
             WHEN  dbo.Graduater_Business.ComeFrom  =   ' HP '   THEN   ' 华普大厦 '  
             WHEN  dbo.Graduater_Business.ComeFrom  =   ' JD '   THEN   ' 精典大厦 '  
             WHEN  dbo.Graduater_Business.ComeFrom  =   ' MC '   THEN   ' 赛马场 '  
             WHEN  ComeFrom  =   ' ZX '   THEN   ' 高指中心 '   END   AS  ComeFromName, 
       dbo.Person_Contact.Address  AS  Address, 
       dbo.Person_Contact.Zip  AS  Zip, 
       dbo.Person_Contact.Telephone  AS  Telephone, 
       dbo.Person_Contact.Mobile  AS  Mobile, 
       dbo.Person_Contact.Email  AS  Email, 
       dbo.Person_Contact.IM  AS  IM, 
       dbo.Person_Skill.ForeignLanguage  AS  ForeignLanguage, 
       dbo.Person_Skill.ForeignLanguageLevel  AS  ForeignLanguageLevel, 
       dbo.Person_Skill.CantoneseLevel  AS  CantoneseLevel, 
       dbo.Person_Skill.MandarinLevel  AS  MandarinLevel, 
       dbo.Person_Skill.Language  AS  Language, 
       dbo.Person_Skill.TechnicalTitle  AS  TechnicalTitle, 
       dbo.Person_Skill.ComputerLevel  AS  ComputerLevel, 
       dbo.Person_EmployPurpose.JobType  AS  JobType, 
       dbo.Person_EmployPurpose.Vocation  AS  Vocation, 
       dbo.Person_EmployPurpose.JobPlace  AS  JobPlace, 
       dbo.Person_EmployPurpose.Salary  AS  Salary, 
       dbo.Person_EmployPurpose.OnJobDate  AS  OnJobDate, 
       dbo.Person_EmployPurpose.CorpType  AS  CorpType, 
       dbo.Person_EmployPurpose.Job  AS  RequireJob, 
        YEAR ( GETDATE ())  -   YEAR (dbo.Person_BasicInfo.Birthday)  AS  Age, 
       dbo.Graduater_Business.EmployType  AS  EmployType, 
       dbo.Graduater_Business.EmployTypeCode  AS  EmployTypeCode, 
       dbo.Graduater_Business.EmployCorpType  AS  EmployCorpType, 
        CASE   WHEN  dbo.Graduater_Business.PrintStatus  =   ' 已打印 '   THEN   ' 已打印 '  
             ELSE   ' 未打印 '   END   AS  PrintStatus, 
       dbo.Graduater_Business.PrintTime  AS  PrintTime, 
        CASE   WHEN  dbo.Graduater_Business.EmployStatus  =   ' 是 '   THEN   ' 已就业 '  
             ELSE   ' 未就业 '   END   AS  EmployStatusView 
   FROM  dbo.Person_BasicInfo 
        INNER   JOIN  dbo.Graduater_Business 
           ON  dbo.Person_BasicInfo.PersonID  =  dbo.Graduater_Business.PersonID 
        LEFT   OUTER   JOIN  dbo.Graduater_GraduaterRegist 
          ON  dbo.Graduater_Business.GradBusinessID  =  dbo.Graduater_GraduaterRegist.GraduaterGUID 
        INNER   JOIN  dbo.Person_Contact 
           ON  dbo.Person_BasicInfo.PersonID  =  dbo.Person_Contact.PersonID 
        INNER   JOIN  dbo.Person_Skill 
           ON  dbo.Person_BasicInfo.PersonID  =  dbo.Person_Skill.PersonID 
        INNER   JOIN  dbo.Person_EmployPurpose 
           ON  dbo.Person_BasicInfo.PersonID  =  dbo.Person_EmployPurpose.PersonID 
OPTION  (FORCE  ORDER )

 

 （5）学习书写专家级的SQL语句 。

    通过上面的步骤，我们已经可以实现自动优化SQL语句，但更重要的是，我们还可以学习如何书写这样高性能的SQL语句。点击界面左方的“Compare Scenarios”按钮，我们可以比较优化方案和原始SQL中的任意2条SQL语句，SQL Tuning会将它们之间的不同之处以不同颜色表示出来，
还可以在下方的“执行计划”中，通过比较两条SQL语句的执行计划的不同，来了解其中的差异（图8）。 

            

                                      图8 “Compare Scenarios”界面

   三、总结

    SQL Tuning等人工智能自动SQL优化工具的出现，为我们节省出大量的时间和精力。借助这些工具的帮助，书写专家级的SQL语句将不再是难事。

   Quest.Central.For.Databases下载地址：
   http://58.251.57.206/down?cid=1669258673&t=14&fmt=&usrinput=Quest.Central&dt=0&ps=0_0&rt=0kbs&plt=0&spd=9

   SQL Tuning操作手册英文版:

   http://files.cnblogs.com/dreamof/SQL.Tuning.rar

 
    注意：该软件试用期只有7天，我这里有注册机，需要的请留Email，到时统一发送！