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PONo real performance gain after index rebuild on SQL Server 2008
 

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  1. PONo real performance gain after index rebuild on SQL Server 2008
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    <p>I have a table whose compound clustered index (<code>int, DateTime</code>) was 99% fragmented.</p> <p>After defragmenting and making sure that statistics were updated, I still get the same response time when I run this query:</p> <pre><code>SELECT * FROM myTable WHERE myIntField = 1000 AND myDateTimeField &gt;= '2012-01-01' and myDateTimeField &lt;= '2012-12-31 23:59:59.999' </code></pre> <p>Well, I see a small response time improvement (like 5-10%) but I was really expected to burst my queries after that index rebuild and stats update.</p> <p>The estimated execution plan is:</p> <ol> <li><code>SELECT Cost: 0%</code></li> <li><code>Clustered Index Seek (Clustered)[MyTable].[IX_MyCompoundIndex] Cost: 100%</code></li> </ol> <p>Is this because the index is a clustered index? Am I missing something?</p>
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    1. USmarc_s
    1. USAdi
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    1. COHow many rows are in the table, vs. how many rows match this query? How wide is the table? How long does it take? Where are you measuring this (Management Studio, your app) and how far away from the data source are you retrieving results?
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      1. PONo real performance gain after index rebuild on SQL Server 2008
      1. USAaron Bertrand
    2. COHave you looked at the statistics? The set could be completely in memory helping explain what you are seeing here.
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      1. PONo real performance gain after index rebuild on SQL Server 2008
      1. USRubbleFord
    3. COWhat is the problem exactly? How many rows are returned? How long does the query take?
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      1. PONo real performance gain after index rebuild on SQL Server 2008
      1. USMartin Smith
 

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