Question

我不确定我是否可以提供足够的答案细节，但我的公司在使用较旧的mssql视图时遇到了性能问题。我已将它缩小到右外连接，但是我不熟悉连接之后没有＆＃34; ON＆＃34;与每个一样，如下面的代码片段。

如何编写以下联接以提高性能或更简单的在Field1 = field2 格式上加入表名的格式？

  FROM    dbo.tblObject AS tblObject_2
            JOIN dbo.tblProspectB2B PB ON PB.Object_ID = tblObject_2.Object_ID
            RIGHT OUTER JOIN dbo.tblProspectB2B_CoordinatorStatus
            RIGHT OUTER JOIN dbo.tblObject
            INNER JOIN dbo.vwDomain_Hierarchy
            INNER JOIN dbo.tblContactUser
            INNER JOIN dbo.tblProcessingFile WITH ( NOLOCK )
            LEFT OUTER JOIN dbo.enumRetentionRealization AS RR ON RR.RetentionRealizationID = dbo.tblProcessingFile.RetentionLeadTypeID
            INNER JOIN dbo.tblLoan
            INNER JOIN dbo.tblObject AS tblObject_1 WITH ( NOLOCK ) ON dbo.tblLoan.Object_ID = tblObject_1.Object_ID ON dbo.tblProcessingFile.Loan_ID = dbo.tblLoan.Object_ID ON dbo.tblContactUser.Object_ID = dbo.tblLoan.ContactOwnerID ON dbo.vwDomain_Hierarchy.Object_ID = tblObject_1.Domain_ID ON dbo.tblObject.Object_ID = dbo.tblLoan.ContactOwnerID ON   dbo.tblProspectB2B_CoordinatorStatus.Object_ID =   dbo.tblLoan.ReferralSourceContactID ON tblObject_2.Object_ID =       dbo.tblLoan.ReferralSourceContactID

Answer 1

您的上一个INNER JOIN有多个ON语句。根据{{3}}问题和答案，此类语法等同于嵌套子查询。

堆叠连接的性能不佳

1 个答案: