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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept id="disable_codegen">
<title>DISABLE_CODEGEN Query Option</title>
<titlealts audience="PDF">
<data name="Category" value="Impala"/>
<data name="Category" value="Impala Query Options"/>
<data name="Category" value="Troubleshooting"/>
<data name="Category" value="Performance"/>
The <codeph>DISABLE_CODEGEN</codeph> 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 <q>illegal
instruction</q> or other hardware-specific message, try setting
<codeph>DISABLE_CODEGEN=true</codeph> and running the query again. If the query succeeds
only when the <codeph>DISABLE_CODEGEN</codeph> option is turned on, submit the problem to
<keyword keyref="support_org"> </keyword> and include that detail in the problem report.
Most queries will run significantly slower with <codeph>DISABLE_CODEGEN=true</codeph>.
In Impala 2.10 and higher, the <codeph>DISABLE_CODEGEN_ROWS_THRESHOLD</codeph>
optimisation automatically disables codegen for small queries because short-running
queries may run faster without the overhead of codegen.
The following values are supported:
<codeph>TRUE</codeph> or <codeph>1</codeph>: Disables codegen.
<codeph>FALSE</codeph> or <codeph>0</codeph>: Enables codegen.
<b>Type:</b> Boolean
<p conref="../shared/impala_common.xml#common/default_false_0"/>