| <?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"> |
| |
| <navtitle>DISABLE_CODEGEN</navtitle> |
| |
| </titlealts> |
| |
| <prolog> |
| <metadata> |
| <data name="Category" value="Impala"/> |
| <data name="Category" value="Impala Query Options"/> |
| <data name="Category" value="Troubleshooting"/> |
| <data name="Category" value="Performance"/> |
| </metadata> |
| </prolog> |
| |
| <conbody> |
| |
| <p> |
| 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. |
| </p> |
| |
| <p> |
| Most queries will run significantly slower with <codeph>DISABLE_CODEGEN=true</codeph>. |
| </p> |
| |
| <p> |
| 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. |
| </p> |
| |
| <p> |
| The following values are supported: |
| <ul> |
| <li> |
| <codeph>TRUE</codeph> or <codeph>1</codeph>: Disables codegen. |
| </li> |
| |
| <li> |
| <codeph>FALSE</codeph> or <codeph>0</codeph>: Enables codegen. |
| </li> |
| </ul> |
| </p> |
| |
| <p> |
| <b>Type:</b> Boolean |
| </p> |
| |
| <p conref="../shared/impala_common.xml#common/default_false_0"/> |
| |
| </conbody> |
| |
| </concept> |