Question

任何人都可以帮我从SQL 2000中提高这个游标逻辑的性能。它在SQl2005和SQL2008中运行良好，但在SQL 2000中运行至少需要20分钟。顺便说一下，我永远不会选择使用游标，我没有编写这段代码，只是试图让它运行得更快。在不久的将来，将此客户端升级到2005/2008不是一种选择。

-------------------------------------------------------------------------------
------- Rollup totals in the chart of accounts hierarchy
-------------------------------------------------------------------------------
DECLARE @B_SubTotalAccountID int, @B_Debits money, @B_Credits money, @B_YTDDebits money, @B_YTDCredits money

DECLARE Bal CURSOR FAST_FORWARD FOR 
 SELECT SubTotalAccountID, Debits, Credits, YTDDebits, YTDCredits FROM xxx 
  WHERE AccountType = 0 AND SubTotalAccountID Is Not Null and (abs(credits)+abs(debits)+abs(ytdcredits)+abs(ytddebits)<>0)
OPEN Bal

FETCH NEXT FROM Bal INTO @B_SubTotalAccountID, @B_Debits, @B_Credits, @B_YTDDebits, @B_YTDCredits

--For Each Active Account
WHILE @@FETCH_STATUS = 0
 BEGIN

 --Loop Until end of subtotal chain is reached
 WHILE @B_SubTotalAccountID Is Not Null
  BEGIN

  UPDATE xxx2
  SET Debits = Debits + @B_Debits,
   Credits = Credits + @B_Credits,
   YTDDebits = YTDDebits + @B_YTDDebits,
   YTDCredits = YTDCredits + @B_YTDCredits
  WHERE GLAccountID = @B_SubTotalAccountID

  SET @B_SubTotalAccountID = (SELECT SubTotalAccountID FROM xxx2 WHERE GLAccountID = @B_SubTotalAccountID)

  END

 FETCH NEXT FROM Bal INTO @B_SubTotalAccountID, @B_Debits, @B_Credits, @B_YTDDebits, @B_YTDCredits

 END

CLOSE Bal
DEALLOCATE Bal

Answer 1

Update xx2
Set Credits = Credits + X1.CreditTotal
    , Debits = Debits + X1.DebitTotal
    , YtdDebits = YtdDebits + X1.YtdDebitTotal
    , YtdCredits = YtdCredits + X1.YtdDebitTotal
From xx2 As X2
    Join    (
            Select SubTotalAccountID, Sum(Debits) As DebitTotal, Sum(Credits) As CreditTotal
                , Sum(YtdDebits) As YtdDebitTotal, Sum(YtdCredits) As YtdCreditTotal
            From xxx
            Where AccountType = 0 
                And SubTotalAccountID Is Not Null 
                And (
                    Credits <> 0
                    Or Debits <> 0
                    Or YtdCredits <> 0
                    Or YtdDebits <> 0
                    )
            Group By SubTotalAccountID
            ) As X1
        On X1.SubTotalAccountID = X2.GLAccountID

如果没有架构，我无法判断xxx表是否会为给定的SubTotalAccountId返回多行。我假设它可以并按此列对值进行分组，以便每个SubTotalAccountId得到一行。

我还在WHERE子句中替换了你对ABS的使用，只需检查零。这应该快得多。

此UPDATE语句应该是光标的完全替代。

Answer 2

一些建议：

1 - 使用分析器告诉你哪一部分运行缓慢 - 你可以获得每个陈述的持续时间

2 - 在过程之外运行初始select语句（游标声明）并检查查询计划。它运行得很快吗？它是否正确使用索引？

3 - 与update语句相同 - 检查查询计划和索引用法

4 - 更新后的'set'语句看起来很奇怪 - 似乎是在@B_SubTotalAccountID中得到一个值，然后立即被'fetch next'替换

使用更好的代码帮助替换此SQL游标

2 个答案: