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| <meta name="DC.Title" content="DISABLE_CODEGEN Query Option" /> |
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| <title>DISABLE_CODEGEN Query Option</title> |
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| <h1 class="title topictitle1" id="ariaid-title1">DISABLE_CODEGEN Query Option</h1> |
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| <div class="body conbody"> |
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| <p class="p"> |
| The <code class="ph codeph">DISABLE_CODEGEN</code> is a debug option, and it's used to work around any |
| issues with Impala's runtime code generation. If a query fails with an <span class="q">"illegal |
| instruction"</span> or other hardware-specific message, try setting |
| <code class="ph codeph">DISABLE_CODEGEN=true</code> and running the query again. If the query succeeds |
| only when the <code class="ph codeph">DISABLE_CODEGEN</code> option is turned on, submit the problem to |
| <span class="keyword"> the appropriate support channel</span> and include that detail in the problem report. |
| </p> |
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| <p class="p"> |
| Most queries will run significantly slower with <code class="ph codeph">DISABLE_CODEGEN=true</code>. |
| </p> |
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| <p class="p"> |
| In Impala 2.10 and higher, the <code class="ph codeph">DISABLE_CODEGEN_ROWS_THRESHOLD</code> |
| optimisation automatically disables codegen for small queries because short-running |
| queries may run faster without the overhead of codegen. |
| </p> |
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| <div class="p"> |
| The following values are supported: |
| <ul class="ul"> |
| <li class="li"> |
| <code class="ph codeph">TRUE</code> or <code class="ph codeph">1</code>: Disables codegen. |
| </li> |
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| <li class="li"> |
| <code class="ph codeph">FALSE</code> or <code class="ph codeph">0</code>: Enables codegen. |
| </li> |
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| </ul> |
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| </div> |
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| <p class="p"> |
| <strong class="ph b">Type:</strong> Boolean |
| </p> |
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| <p class="p"> |
| <strong class="ph b">Default:</strong> <code class="ph codeph">false</code> (shown as 0 in output of <code class="ph codeph">SET</code> |
| statement) |
| </p> |
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| </div> |
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| <div class="related-links"> |
| <div class="familylinks"> |
| <div class="parentlink"><strong>Parent topic:</strong> <a class="link" href="../topics/impala_set.html">SET Statement</a></div> |
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