Question

我在以下查询中运行sql analyzer

SELECT bl.Invoice_Number, bl.Date_Invoice, ti.TranNo, bt.Description,
    CONVERT(decimal(15,2), bl.Invoice_Amount) AS Invoice_Amount, co.Company_ID, co.Account_Nbr,
    isnull(bl.Reference,' ') as Reference, bl.Billing_Log_RecID AS BillingKey
    FROM [CONN.domain.NET].cwwebapp.dbo.Billing_Log bl
    LEFT JOIN [App].dob.tarInvoice ti
        ON bl.Invoice_Number = dbo._fnStripLeadZeros(ti.TranNo)
    INNER JOIN [CONN.domain.NET].cwwebapp.dbo.Billing_Type bt
        ON bl.Billing_Type_ID = bt.Billing_Type_ID
    LEFT JOIN [CONN.domain.NET].cwwebapp.dbo.Company co
        ON  bl.Company_RecID = co.Company_RecID
    WHERE bl.Date_Invoice >= '2009-05-05'
        AND ti.TranNo IS NULL
        AND bl.Invoice_Amount <> 0
        AND bl.Billing_Type_ID <> 'D'
        AND bl.Billing_Type_ID <> 'P'
--      AND bl.Billing_Type_ID <> 'M'
Order By bl.Invoice_Number

查询在[App]服务器上运行，并连接到[Conn] sql server进行连接并且图表告诉我

remote query cost : 62%
customered index scan [App].[dbo].tarInvoice.[PK__...  Cost : 34%

此查询需要2分钟才能运行。关于如何确定如何提高运行效率的任何想法？我猜它与连接到同一网络上的另一个sql server有关。

提前感谢。

Answer 1

您正在对tarInvoice聚集索引进行完整扫描（触摸每个索引条目），看看是否可以删除函数调用dbo._fnStripLeadZeros（ti.TranNo），以便它将使用索引。

可能会将前导零添加到bl.Invoice_Number并加入到未改变的ti.TranNo

修改

添加不带前导零的计算列并添加索引：

ALTER TABLE dbo.tarInvoice ADD TranNoZeroFree AS Convert(int,TranNo) PERSISTED GO CREATE NONCLUSTERED INDEX IX_tarInvoice_TranNoZeroFree ON dbo.tarInvoice (TranNoZeroFree) WITH( STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO

Answer 2

尝试将远程服务器添加为linked server。

Answer 3

只使用了一个本地表，因此您可以将更多查询转移到另一台服务器：

select *
from openquery([CONN.domain.NET],'
SELECT bl.Invoice_Number, bl.Date_Invoice, ti.TranNo, bt.Description,
    CONVERT(decimal(15,2), bl.Invoice_Amount) AS Invoice_Amount,
    co.Company_ID, co.Account_Nbr, isnull(bl.Reference,'' '') as Reference,
    bl.Billing_Log_RecID AS BillingKey
    FROM cwwebapp.dbo.Billing_Log bl
    INNER JOIN cwwebapp.dbo.Billing_Type bt
        ON bl.Billing_Type_ID = bt.Billing_Type_ID
    LEFT JOIN cwwebapp.dbo.Company co
        ON      bl.Company_RecID = co.Company_RecID
    WHERE bl.Date_Invoice >= ''2009-05-05''
        AND bl.Invoice_Amount <> 0
        AND bl.Billing_Type_ID <> ''D''
        AND bl.Billing_Type_ID <> ''P''
') remote
LEFT JOIN tarInvoice ti
    ON remote.Invoice_Number = dbo._fnStripLeadZeros(ti.TranNo)
WHERE ti.TranNo IS NULL
Order By remote.Invoice_Number

不确定确切的语法，只是试图指出可能的改进方向。

Answer 4

我还建议如果你必须在查询中转换数据，例如： CONVERT（十进制（15,2），bl.Invoice_Amount）那么你需要考虑重构数据库以使用正确的数据类型。

SQL查询分析器：你如何降低“成本”？

4 个答案: