如何正確索引多個字段以獲得更快的結果

我有一個包含ConChainNum，Control和TransDate的索引，並且我只重建了索引。我與工作表有100多萬條記錄和下面的查詢不返回任何結果：如何正確索引多個字段以獲得更快的結果

select * from sbt_pos_sales 
where conchainnum = 810 and 
     control = 852013688 and 
     transdate = 20120712

鑑於我與where子句中的三個字段專門做出一個索引，我真的希望幾乎立即結果，但花了大約半分鐘的時間告訴我那裏沒有結果。

有人可以向我解釋爲什麼這個指數沒有使它比這更快，如果我能以某種方式做它不同，使其更快？

執行計劃：

<?xml version="1.0" encoding="utf-16"?> 
<ShowPlanXML xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" Version="1.1.1" Build="10.0.5500.0" xmlns="http://schemas.microsoft.com/sqlserver/2004/07/showplan"> 
    <BatchSequence> 
    <Batch> 
     <Statements> 
     <StmtSimple StatementCompId="1" StatementEstRows="20.2265" StatementId="1" StatementOptmLevel="FULL" StatementSubTreeCost="348.687" StatementText="SELECT * FROM [ngdwdb]..[sbt_pos_sales] WHERE [conchainnum][email protected] AND [control][email protected] AND [transdate][email protected]" StatementType="SELECT" QueryHash="0x11B117D9A8C6DF58" QueryPlanHash="0xBA3EFC04623601F6"> 
      <StatementSetOptions ANSI_NULLS="true" ANSI_PADDING="true" ANSI_WARNINGS="true" ARITHABORT="true" CONCAT_NULL_YIELDS_NULL="true" NUMERIC_ROUNDABORT="false" QUOTED_IDENTIFIER="true" /> 
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       <OutputList> 
       <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="RowIdent" /> 
       <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="ConChainNum" /> 
       <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="Control" /> 
       <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="TransDate" /> 
       <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="ControlGS" /> 
       <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="UPC_UCP" /> 
       <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="DateSold" /> 
       <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="Price_UCP" /> 
       <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="Store" /> 
       <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="QtySold" /> 
       <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="FileName" /> 
       <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="IssueCode" /> 
       <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="DealerNum" /> 
       </OutputList> 
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        <OutputList> 
        <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="RowIdent" /> 
        <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="ConChainNum" /> 
        <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="Control" /> 
        <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="TransDate" /> 
        <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="ControlGS" /> 
        <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="UPC_UCP" /> 
        <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="DateSold" /> 
        <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="Price_UCP" /> 
        <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="Store" /> 
        <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="QtySold" /> 
        <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="FileName" /> 
        <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="IssueCode" /> 
        <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="DealerNum" /> 
        </OutputList> 
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         <OutputList> 
         <ColumnReference Column="Bmk1000" /> 
         <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="ConChainNum" /> 
         <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="Control" /> 
         <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="TransDate" /> 
         <ColumnReference Column="Expr1008" /> 
         </OutputList> 
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          <ColumnReference Column="Expr1008" /> 
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          <OutputList> 
          <ColumnReference Column="Bmk1000" /> 
          <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="ConChainNum" /> 
          <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="Control" /> 
          <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="TransDate" /> 
          </OutputList> 
          <RunTimeInformation> 
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          <RunTimeCountersPerThread Thread="3" ActualRows="0" ActualEndOfScans="1" ActualExecutions="1" /> 
          <RunTimeCountersPerThread Thread="2" ActualRows="0" ActualEndOfScans="1" ActualExecutions="1" /> 
          <RunTimeCountersPerThread Thread="7" ActualRows="0" ActualEndOfScans="1" ActualExecutions="1" /> 
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           <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="ConChainNum" /> 
           </DefinedValue> 
           <DefinedValue> 
           <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="Control" /> 
           </DefinedValue> 
           <DefinedValue> 
           <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="TransDate" /> 
           </DefinedValue> 
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             <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="ConChainNum" /> 
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             <Const ConstValue="(810)" /> 
             </ScalarOperator> 
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           <Logical Operation="AND"> 
            <ScalarOperator> 
            <Compare CompareOp="EQ"> 
             <ScalarOperator> 
             <Convert DataType="int" Style="0" Implicit="true"> 
              <ScalarOperator> 
              <Identifier> 
               <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="Control" /> 
              </Identifier> 
              </ScalarOperator> 
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             </ScalarOperator> 
             <ScalarOperator> 
             <Const ConstValue="(852013688)" /> 
             </ScalarOperator> 
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            </ScalarOperator> 
            <ScalarOperator> 
            <Compare CompareOp="EQ"> 
             <ScalarOperator> 
             <Convert DataType="int" Style="0" Implicit="true"> 
              <ScalarOperator> 
              <Identifier> 
               <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="TransDate" /> 
              </Identifier> 
              </ScalarOperator> 
             </Convert> 
             </ScalarOperator> 
             <ScalarOperator> 
             <Const ConstValue="(20120712)" /> 
             </ScalarOperator> 
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         <OutputList> 
         <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="RowIdent" /> 
         <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="ControlGS" /> 
         <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="UPC_UCP" /> 
         <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="DateSold" /> 
         <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="Price_UCP" /> 
         <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="Store" /> 
         <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="QtySold" /> 
         <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="FileName" /> 
         <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="IssueCode" /> 
         <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="DealerNum" /> 
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         </RunTimeInformation> 
         <IndexScan Lookup="true" Ordered="true" ScanDirection="FORWARD" ForcedIndex="false" ForceSeek="false" NoExpandHint="false"> 
         <DefinedValues> 
          <DefinedValue> 
          <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="RowIdent" /> 
          </DefinedValue> 
          <DefinedValue> 
          <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="ControlGS" /> 
          </DefinedValue> 
          <DefinedValue> 
          <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="UPC_UCP" /> 
          </DefinedValue> 
          <DefinedValue> 
          <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="DateSold" /> 
          </DefinedValue> 
          <DefinedValue> 
          <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="Price_UCP" /> 
          </DefinedValue> 
          <DefinedValue> 
          <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="Store" /> 
          </DefinedValue> 
          <DefinedValue> 
          <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="QtySold" /> 
          </DefinedValue> 
          <DefinedValue> 
          <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="FileName" /> 
          </DefinedValue> 
          <DefinedValue> 
          <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="IssueCode" /> 
          </DefinedValue> 
          <DefinedValue> 
          <ColumnReference Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" Column="DealerNum" /> 
          </DefinedValue> 
         </DefinedValues> 
         <Object Database="[NGDWDB]" Schema="[dbo]" Table="[SBT_POS_SALES]" TableReferenceId="-1" IndexKind="Heap" /> 
         <SeekPredicates> 
          <SeekPredicateNew> 
          <SeekKeys> 
           <Prefix ScanType="EQ"> 
           <RangeColumns> 
            <ColumnReference Column="Bmk1000" /> 
           </RangeColumns> 
           <RangeExpressions> 
            <ScalarOperator ScalarString="[Bmk1000]"> 
            <Identifier> 
             <ColumnReference Column="Bmk1000" /> 
            </Identifier> 
            </ScalarOperator> 
           </RangeExpressions> 
           </Prefix> 
          </SeekKeys> 
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         </SeekPredicates> 
         </IndexScan> 
        </RelOp> 
        </NestedLoops> 
       </RelOp> 
       </Parallelism> 
      </RelOp> 
      <ParameterList> 
       <ColumnReference Column="@3" ParameterCompiledValue="(20120712)" ParameterRuntimeValue="(20120712)" /> 
       <ColumnReference Column="@2" ParameterCompiledValue="(852013688)" ParameterRuntimeValue="(852013688)" /> 
       <ColumnReference Column="@1" ParameterCompiledValue="(810)" ParameterRuntimeValue="(810)" /> 
      </ParameterList> 
      </QueryPlan> 
     </StmtSimple> 
     </Statements> 
    </Batch> 
    </BatchSequence> 
</ShowPlanXML>

來源

2012-07-18 Brandon Moore

有幾件事可能會放慢速度。 1.有多少列*返回？ 2，你總是使用全部3列嗎？你也可能需要分開索引。你看過預計的執行計劃嗎？ – Limey 2012-07-18 16:57:07

需要更多信息。您的索引是否包含其他列或僅包含這三個列？索引是否聚集？如果沒有，是否有聚集索引？你有沒有檢查過（如果可以，你能發佈）執行計劃嗎？ – mwigdahl 2012-07-18 16:57:19

@Limey 1.十三，但爲什麼在這種情況下，因爲沒有行返回？是的。我正在研究執行計劃。 – 2012-07-18 17:03:56

而不是保持填補了意見，我會正式將此作爲一個答案......

根據你的執行計劃，我建議上添加一個聚集索引桌子。很難100％確定發生了什麼，但RID查找是一個問題。

當沒有與該表關聯的集羣密鑰時，會發生RID查找。在非聚簇索引中，聚簇鍵在非聚簇索引中被複制（如果存在），可以在找到索引條目後加速所需的任何行訪問。在一個堆（非聚簇索引的表）中，你沒有該聚簇鍵，所以你必須在堆中查找它。

這就是爲什麼您的執行計劃中有一個INNER JOIN，即使SQL中沒有JOIN也是如此。將聚類應用於表中的主鍵應該消除這種連接，並使用簡單的索引查找。

儘管目前的計劃顯示它現在佔用了89％的時間，但我敢打賭，通過表格中的聚集索引，您可以將其簡化爲簡單（且更快）的索引查找。

編輯：

讓我看看你的執行計劃XML後，修改這個。雖然集羣關鍵點應該仍然有幫助，但真正的問題是索引中的數據類型。在索引查找我展示

CONVERT_IMPLICIT(int,[NGDWDB].[dbo].[SBT_POS_SALES].[Control],0)=(852013688) AND CONVERT_IMPLICIT(int,[NGDWDB].[dbo].[SBT_POS_SALES].[TransDate],0)=(20120712)

，這是告訴我，控制和TransDate是不相同的數據類型，你是在你的查詢提供。如果你解決這個問題，不需要轉換，你很可能會在查詢中看到巨大的加速。

來源

2012-07-18 17:40:44 mwigdahl

謝謝。如果你知道答案，這裏有一個側面的問題：如果我在這個表中做了一個批量插入（我明白忽略了這些索引），那麼對於我每次做一個或者定期重建索引都很重要也許一週一次，如果我每天大約30k行進行一次大容量插入）？ – 2012-07-18 17:54:23

另外一個選擇是隻選擇索引中包含的列 - 這將消除對任何「RID查找」的需要（或者一旦聚集索引就位時就進行「查詢」） – 2012-07-18 17:58:50

啊哈，轉換是最大的罪魁禍首，做「選擇1」而不是*也有幫助。現在我有了我期待的直接結果。多謝你們！ – 2012-07-18 18:11:43

如何正確索引多個字段以獲得更快的結果

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