查詢與ROW_NUMBER（）花費過多時間

Question

我在DB各地90K的記錄，我運行此查詢：

它需要太多的時間（約4秒）：

SELECT * FROM (SELECT 
    ROW_NUMBER() OVER (Order By DocumentID desc) peta_rn, peta_query.* From 
    (
      Select d.DocumentID, d.IsReEfiled, d.IGroupID, d.ITypeID, d.RecordingDateTime, dbo.GetLatestStatusDateTime(d.DocumentID) as LatestStatusDatetime, 
        dbo.FnCanChangeDocumentStatus(d.DocumentStatusID,d.DocumentID) as CanChangeStatus, d.IDate, d.InstrumentID, d.DocumentStatusID,ig.Abbreviation as IGroupAbbreviation, 
        u.Username, j.JDAbbreviation, inf.DocumentName, 
        it.Abbreviation as ITypeAbbreviation, d.DocumentDate, ds.Abbreviation as DocumentStatusAbbreviation, 
        dbo.GetFlatDocumentName(d.DocumentID) as FlatDocumentName 
        From Documents d Inner Join IGroupes ig On d.IGroupID = ig.IGroupID 
          Left Join ITypes it On d.ITypeID = it.ITypeID 
          Left Join Users u On u.UserID = d.UserID 
          Left Join DocumentStatuses ds On d.DocumentStatusID = ds.DocumentStatusID 
          Left Join InstrumentFiles inf On d.DocumentID = inf.DocumentID 
          Inner Join Jurisdictions j on j.JurisdictionID = d.JurisdictionID       
    ) as peta_query) peta_paged WHERE peta_rn>12000 AND peta_rn<=12100 

然而，這第二查詢執行1秒：

SELECT * FROM (SELECT 
    peta_query.* From 
    (
      Select ROW_NUMBER() OVER (Order By d.DocumentID desc) peta_rn, d.DocumentID, d.IsReEfiled, d.IGroupID, d.ITypeID, d.RecordingDateTime, dbo.GetLatestStatusDateTime(d.DocumentID) as LatestStatusDatetime, 
        dbo.FnCanChangeDocumentStatus(d.DocumentStatusID,d.DocumentID) as CanChangeStatus, d.IDate, d.InstrumentID, d.DocumentStatusID,ig.Abbreviation as IGroupAbbreviation, 
        u.Username, j.JDAbbreviation, inf.DocumentName, 
        it.Abbreviation as ITypeAbbreviation, d.DocumentDate, ds.Abbreviation as DocumentStatusAbbreviation, 
        dbo.GetFlatDocumentName(d.DocumentID) as FlatDocumentName 
        From Documents d Inner Join IGroupes ig On d.IGroupID = ig.IGroupID 
          Left Join ITypes it On d.ITypeID = it.ITypeID 
          Left Join Users u On u.UserID = d.UserID 
          Left Join DocumentStatuses ds On d.DocumentStatusID = ds.DocumentStatusID 
          Left Join InstrumentFiles inf On d.DocumentID = inf.DocumentID 
          Inner Join Jurisdictions j on j.JurisdictionID = d.JurisdictionID       
    ) as peta_query) peta_paged WHERE peta_rn>12000 AND peta_rn<=12100 

我的問題是：

1）你能否建議爲什麼我的第一個查詢需要這麼長時間來執行？我想優化我的第一個查詢，因爲它是由一個自動化程序生成的（它的源代碼有，但我不能移動Select中的RowNumber）。

2）執行此操作的時間也取決於peta_rn。如果我給peta_rn> 50000和peta_rn < = 50100，則需要執行無望的時間。你能否也請建議爲什麼要執行的時間取決於我試圖讀取的行，因爲最終我只試圖一次讀取100行。

Answer 1

只是爲了它的樂趣 - 你可以試試這個CTE，看看它是如何執行的？我不完全理解爲什麼你有三個嵌套子查詢有....

;WITH PetaQuery AS 
(
    SELECT 
     ROW_NUMBER() OVER (ORDER BY d.DocumentID DESC) peta_rn, 
     d.DocumentID, d.IsReEfiled, d.IGroupID, d.ITypeID, d.RecordingDateTime, 
     dbo.GetLatestStatusDateTime(d.DocumentID) as LatestStatusDatetime, 
     dbo.FnCanChangeDocumentStatus(d.DocumentStatusID,d.DocumentID) as CanChangeStatus, 
     d.IDate, d.InstrumentID, d.DocumentStatusID,ig.Abbreviation as IGroupAbbreviation, 
     u.Username, j.JDAbbreviation, inf.DocumentName, 
     it.Abbreviation as ITypeAbbreviation, d.DocumentDate, ds.Abbreviation as DocumentStatusAbbreviation, 
     dbo.GetFlatDocumentName(d.DocumentID) as FlatDocumentName 
    FROM 
     Documents d 
    INNER JOIN 
     IGroupes ig On d.IGroupID = ig.IGroupID 
    LEFT OUTER JOIN 
     ITypes it On d.ITypeID = it.ITypeID 
    LEFT OUTER JOIN 
     Users u On u.UserID = d.UserID 
    LEFT OUTER JOIN 
     DocumentStatuses ds On d.DocumentStatusID = ds.DocumentStatusID 
    LEFT OUTER JOIN 
     InstrumentFiles inf On d.DocumentID = inf.DocumentID 
    INNER JOIN 
     Jurisdictions j on j.JurisdictionID = d.JurisdictionID       
) 
SELECT * FROM PetaQuery 
WHERE peta_rn > 12000 AND peta_rn <= 12100 

這是否具有相同的響應時間爲原始查詢？

如果是這樣，請檢查：

• 你有你的所有外鍵索引（IGroupID，ITypeID，UserID，DocumentStatusID，DocumentID，JurisdictionID）？這對快速加入性能至關重要