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
SQL Server 索引结构及其使用(一)
SQL中查询数据表字段名称的查询语句
SQL Server 索引结构及其使用(二)
SQL技巧:使用SQL子选择来合并查询
如何恢复/修复MS SQL数据库的MDF文件
获取SQL Server元数据的几种方法
在SQL Server中通过原子建立分子查询
保护SQL Server数据库的十个步骤介绍
SQL Server数据库崩溃后的恢复方法简介
SQL Server与Oracle、DB2的性能比较
SQL Server中用索引视图查看性能状况
利用SQL Server系统函数进行代码存档
将 MS SQL Server 2005 SP2 整合到安装文件
如何改进SQL Server安全系统
SQL Server管理常用的SQL和T-SQL简介
精华推荐:SQL Server的用户及权限
Sql server 如何得到汉字的声母
sql server中order by部分使用方式
在SQLServer中用XQuery分解XML数据
两个sql server 2000的通用分页存储过程

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: 42 ::
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