【探讨】索引视图如何提高性能
2010-01-25 00:00:00 来源:WEB开发网最近的一个项目中,由于数据量特别大,导致生成一个报表需要等待10多分钟,所以必须对系统进行优化,跟踪程序后发现数据是从由六个表联接而成的视图中过滤出来的,并且六个表中每个表中的数据都是百万级的,这样联接后效率可想而知了?所以得先对视图进行优化,检查这六个表后发现其中的两个表未建索引,于是马上对其设置索引,再把select的没用字段去除后,再重新执行一下查询语句后,发现效率提高了差不多20%,但是总的来说时间还是比较长,看来还得继续改进。听朋友说索引视图可以大大提高效率,于是从网上查找了一些关于索引视图的资料,并对其进行了简单学习,现总结如下:
一、实例
1、 优化前的视图(执行select * from Query_NoEmployRegist用时127s)
代码
1 SET ANSI_NULLS ON
2 GO
3 SET QUOTED_IDENTIFIER ON
4 GO
5 ALTER VIEW [dbo].[Query_NoEmployRegist]
6 AS
7 SELECT dbo.Person_BasicInfo.*, dbo.Graduater_GraduaterRegist.RegistNO AS RegistNO,
8 dbo.Graduater_GraduaterRegist.RegistTime AS BaoDaoTime,
9 dbo.Graduater_GraduaterRegist.RegistMan AS RegistMan,
10 dbo.Graduater_Business.ComeFrom AS ComeFrom,
11 dbo.Graduater_Business.Code AS Code, dbo.Graduater_Business.Status AS Status,
12 dbo.Graduater_Business.ApproveResult AS ApproveResult,
13 dbo.Graduater_Business.NewCorp AS NewCorp,
14 dbo.Graduater_Business.CommendNumber AS CommendNumber,
15 dbo.Graduater_Business.EmployStatus AS EmployStatus,
16 dbo.Graduater_Business.NewCommendTime AS NewCommendTime,
17 dbo.Graduater_Business.GetSource AS GetSource,
18 dbo.Graduater_Business.EmployTime AS EmployTime,
19 dbo.Graduater_Business.Job AS Job, dbo.Graduater_Business.FillMan AS FillMan,
20 dbo.Graduater_Business.FillTime AS FillTime,
21 dbo.Graduater_Business.IsCommendOK AS IsCommendOK,
22 dbo.Graduater_Business.ApproveUser AS ApproveUser,
23 dbo.Graduater_Business.ApproveTime AS ApproveTime,
24 dbo.Graduater_Business.RegistTime AS RegistTime,
25 dbo.Graduater_Business.EmployCorp AS EmployCorp,
26 dbo.Graduater_Business.JobRemark AS JobRemark,
31 dbo.Person_Contact.Address AS Address, dbo.Person_Contact.Zip AS Zip,
32 dbo.Person_Contact.Telephone AS Telephone, dbo.Person_Contact.Mobile AS Mobile,
33 dbo.Person_Contact.Email AS Email, dbo.Person_Contact.IM AS IM,
34 dbo.Person_Skill.ForeignLanguage AS ForeignLanguage,
35 dbo.Person_Skill.ForeignLanguageLevel AS ForeignLanguageLevel,
36 dbo.Person_Skill.CantoneseLevel AS CantoneseLevel,
37 dbo.Person_Skill.MandarinLevel AS MandarinLevel,
38 dbo.Person_Skill.Language AS Language,
39 dbo.Person_Skill.TechnicalTitle AS TechnicalTitle,
40 dbo.Person_Skill.ComputerLevel AS ComputerLevel,
41 dbo.Person_EmployPurpose.JobType AS JobType,
42 dbo.Person_EmployPurpose.Vocation AS Vocation,
43 dbo.Person_EmployPurpose.JobPlace AS JobPlace,
44 dbo.Person_EmployPurpose.Salary AS Salary,
45 dbo.Person_EmployPurpose.OnJobDate AS OnJobDate,
46 dbo.Person_EmployPurpose.CorpType AS CorpType,
49 dbo.Graduater_Business.EmployType AS EmployType,
50 dbo.Graduater_Business.EmployTypeCode AS EmployTypeCode,
51 dbo.Graduater_Business.EmployCorpType AS EmployCorpType
56 FROM dbo.Person_BasicInfo INNER JOIN
57 dbo.Graduater_Business ON
58 dbo.Person_BasicInfo.PersonID = dbo.Graduater_Business.PersonID LEFT OUTER JOIN
59 dbo.Graduater_GraduaterRegist ON
60 dbo.Graduater_Business.GradBusinessID = dbo.Graduater_GraduaterRegist.GraduaterGUID
61 INNER JOIN
62 dbo.Person_Contact ON
63 dbo.Person_BasicInfo.PersonID = dbo.Person_Contact.PersonID INNER JOIN
64 dbo.Person_Skill ON
65 dbo.Person_BasicInfo.PersonID = dbo.Person_Skill.PersonID INNER JOIN
66 dbo.Person_EmployPurpose ON
67 dbo.Person_BasicInfo.PersonID = dbo.Person_EmployPurpose.PersonID
68 GO
69 SET ANSI_NULLS OFF
70 GO
71 SET QUOTED_IDENTIFIER OFF
72 GO
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