当前位置: 首页 > 图文教程 > 数据库 > MSSQL > SQL优化实例:从运行30分钟到运行只要30秒

MSSQL
详解SQL Server中数据库快照工作原理
VB应用程序访问SQL Server的常用方法
SQL Server特殊磁带备份及恢复设计
基于SQL Server的C/S数据库应用系统
如何实现SQL Server 2005快速Web分页
关于SQL Server数据库中转储设备分析
从外到内提高SQL Server数据库性能
准备SQL Server 2008透明数据加密
快速升级MySQL系统表
解析:在SQL Server下数据库链接的使用
细化解析:SQL Server 2005 数据库镜像
轻松接触SQL Server 2000实例的命名规则
SQL提供的进行数据传输的实用程序—BCP
SQL Server 2000 作数据库服务器的优点
解析:正确的理解SQL Server和XML支持
轻松了解数据库计算机的概念和发展方向
解析SQL Server数据体系和应用程序逻辑
SQL进行排序、分组、统计的10个新技巧
教你怎样打造SQL Server2000的安全策略
解析SQL Server 2005 溢用之:合并列值

MSSQL 中的 SQL优化实例:从运行30分钟到运行只要30秒


出处:互联网   整理: 软晨网(RuanChen.com)   发布: 2009-10-30   浏览: 119 ::
收藏到网摘: n/a

 以下的SQL语句在服务器需要运行长达30分钟才能完成:
SELECT     dbo.ComFlow.ComFlowCode, dbo.ComFlow.ComCode, dbo.ComFlow.CustCode, dbo.ComFlow.DepartCode, dbo.ComFlow.SaleCode,
                      dbo.ComFlow.EmpCode, dbo.ComFlow.Quantity * dbo.Commodity.ConvertRate AS Quantity, CONVERT(datetime, DATENAME(yyyy,
                      dbo.ComFlow.FlowDate) + '-' + DATENAME(mm, dbo.ComFlow.FlowDate) + '-' + DATENAME(dd, dbo.ComFlow.FlowDate)) AS FlowDate,
                      dbo.ComFlow.SalType, dbo.Employee.DepartCode AS DepartIn, dbo.Sale.DepartCode AS DepartOut,
                      dbo.ComFlow.Quantity * dbo.Commodity.TradePrice * dbo.Commodity.Discount / 100 AS Total, dbo.Department.GrpCode AS GrpCodeIn,
                      Department1.GrpCode AS GrpCodeOut
FROM         dbo.ComFlow INNER JOIN
                      dbo.Customer ON
                dbo.ComFlow.SalType IN (N'促销', N'流向退货', N'多级流向') AND dbo.ComFlow.CustCode = dbo.Customer.CustCode
                Or ComFlow_1.SalType IN (N'自然流向', N'自然流向退货') AND ComFlow_1.OutCustCode = Customer_1.CustCode
            INNER JOIN
                      dbo.CustomerRelation ON dbo.ComFlow.ComCode = dbo.CustomerRelation.ComCode AND
                      dbo.CustomerRelation.CustCode = dbo.Customer.CustCode INNER JOIN
                      dbo.Employee ON dbo.CustomerRelation.EmpCode = dbo.Employee.EmpCode INNER JOIN
                      dbo.Sale ON dbo.ComFlow.SaleCode = dbo.Sale.SaleCode INNER JOIN
                      dbo.Department ON dbo.Department.DepartCode = dbo.Employee.DepartCode INNER JOIN
                      dbo.Department AS Department1 ON Department1.DepartCode = dbo.Sale.DepartCode AND
                      dbo.Department.GrpCode <> Department1.GrpCode INNER JOIN
                      dbo.Commodity ON dbo.ComFlow.ComCode = dbo.Commodity.ComCode
WHERE     (NOT (dbo.ComFlow.SalType = N'流向退货')) OR
                      (NOT (dbo.Customer.Type = N'医药公司'))
虽然说,我们使用这个语句的应用是一个BI应用,实时性要求不高,但是,我觉得没有道理会运行这么久,应该有办法优