【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：   

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：  

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:

   https://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！