sql-server - SQL Server 优化查询

Question

有谁知道如何优化这个查询？如果我运行此查询并且生成 11 行需要超过 10 分钟

SELECT DISTINCT th.e_id,
                b_number,
                TQH.supplier_id AS VENDOR_ID,
                s.suppliername AS VENDOR_NAME,
                BUYER_POS,
                TQH.quotation_number AS QUOTATION_NO,
                TQH.contact_person AS CONTRACTOR_REP,
                TQD.tqd_currency_id AS CURRENCY_ID
FROM Tender_Header TH
INNER JOIN Tender_Quotation_Header TQH ON TH.e_id = TQH.e_id
INNER JOIN Tender_Quotation_Type TQT ON TQH.tqh_id = TQT.tqh_id
INNER JOIN Tender_Quotation_Detail TQD ON TQT.tqt_id = TQD.tqt_id
INNER JOIN EVPM.DBO.vwsupplier S ON TQH.supplier_id = S.supplierid
INNER JOIN Tender_Item TI ON TI.item_id = TQD.item_id
INNER JOIN Tender_Proposal TP ON tp.e_id = th.e_id
WHERE (TH.act_id = 46)
  AND (ISNULL(TQD.is_copied, '0') = '0')
  AND (tqd.tqd_result = 1
       OR tqh.resultpackage = 1)
  AND (b_number LIKE 'SM%'
       OR b_number_ref LIKE 'SM%')
  AND b_number NOT IN
    (SELECT eproc_id
     FROM newkimap.dbo.exp_mts_tender_main)

Answer 1

如果不了解您的数据库（表、索引），就很难为您提供帮助。你应该考虑：

• 将“不在”更改为“不存在” http://sqlinthewild.co.za/index.php/2010/02/18/not-exists-vs-not-in/
• 你应该在列 b_number 和 _b_number_ref 上有索引

马辛·帕兹吉尔