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我的数据库中有大约 90k 条记录，我运行以下查询：

这需要太多时间（大约 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

但是，第二个查询在 1 秒内执行：

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

我的问题是：

1）您能否建议为什么我的第一个查询需要这么长时间才能执行？我想优化我的第一个查询，因为它是由一个自动化程序生成的（我确实有它的源，但我不能在 Select 中移动 RowNumber）。

2)执行时间也取决于 peta_rn。如果我给 peta_rn > 50000 和 peta_rn <= 50100，则执行所需的时间非常长。您能否还建议为什么执行时间取决于我尝试获取的行，因为最终我一次只尝试获取 100 行。

4

1 回答 1

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只是为了好玩——你能试试这个 CTE 看看它的表现如何？我不完全明白为什么你在那里有三个嵌套的子查询......

;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

这是否与您的原始查询具有相同的响应时间？

如果是这样，请检查：

  • 你的所有外键（IGroupID, ITypeID, UserID, DocumentStatusID, DocumentID, JurisdictionID）都有索引吗？这对于快速 JOIN 性能至关重要
于 2012-10-17T05:09:54.470 回答