如何優化我的查詢？

Question

我編寫了這段代碼，它可以查找下來的節點並計算上下小時。此代碼有效，但我想知道其他方式或優化此代碼？計算停機時間的最佳方法是什麼？有什麼方式（交互方式），用戶可以輸入日期和時間間隔？

 
SELECT q1.nodeid, q1.VendorIcon, q1.Caption, q1.IP_Address, 
q1.OutageDurationInMinutes, 
q2.TimeUp 

FROM 
(SELECT 
    Nodes.NodeID AS NodeID, ltrim(rtrim(Nodes.Caption)) Caption, Nodes.VendorIcon,Nodes.IP_Address, 
    sum(DATEDIFF(hh, StartTime.EventTime, EndTime.EventTime)) as OutageDurationInMinutes 

FROM Events StartTime 
Left join Events EndTime On 
    EndTime.EventType = '5' and 
    EndTime.NetObjectType = 'N' and 
    EndTime.NetworkNode = StartTime.NetworkNode and 
    EndTime.EventTime = 
        (
         Select 
          min(EventTime) 
         from Events 
         where 
          EventTime>StartTime.EventTime and 
          EventType = '5' and 
          NetObjectType = 'N' and 
          NetworkNode = StartTime.NetworkNode 
        )  
INNER JOIN Nodes ON 
    StartTime.NetworkNode = Nodes.NodeID 
WHERE 
    Nodes.Department = '4' AND 
    StartTime.EventType = 1 AND 
    StartTime.NetObjectType = 'N' AND 
    StartTime.eventtime between dateadd(M, -1, getdate()) and getdate() 

Group by 
    Nodes.NodeID,Nodes.Caption, Nodes.VendorIcon,Nodes.IP_Address, Nodes.LastBoot 
) q1 

INNER JOIN 

(SELECT 
     Nodes.NodeID AS NodeID 
     ,ltrim(rtrim(Caption)) Caption 
     ,VendorIcon 
     ,Ip_Address 
     ,DateDiff(hour,Nodes.LastBoot,GetDate()) AS HoursUp 
     ,CONVERT(VARCHAR(40), DATEDIFF(minute, Nodes.LastBoot, GETDATE())/(24*60)) 
      + ' days, ' 
      + CONVERT(VARCHAR(40), DATEDIFF(minute, Nodes.LastBoot, GETDATE())%(24*60)/60) 
    + ' hours, and ' 
    + CONVERT(VARCHAR(40), DATEDIFF(minute, Nodes.LastBoot, GETDATE())%60) 
    + ' minutes.' AS TimeUp 
FROM [Nodes] 
Where 

LastBoot between dateadd(day, -30, getdate()) and getdate()) q2 on q1.NodeID=q2.NodeID 

Order by Caption 

Answer 1

我想知道任何其他方式或 優化此代碼？

我建議查看一下查詢執行計劃。

有什麼辦法（交互方式），其 用戶可以輸入日期和時間 間隔？

你可以只確定值，在運行查詢之前，並在查詢中使用這些參數（我不知道但什麼叫你的查詢，它是一個存儲過程？）