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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="expand_complex_types">
<title>EXPAND_COMPLEX_TYPES Query Option</title>
<titlealts audience="PDF"><navtitle>EXPAND COMPLEX TYPES</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="Querying"/>
<data name="Category" value="Developers"/>
<data name="Category" value="Data Analysts"/>
</metadata>
</prolog>
<conbody>
<p>
<indexterm audience="hidden">EXPAND_COMPLEX_TYPES Query Option</indexterm> Older versions of
Impala did not support complex types in the select list, and therefore a <codeph>SELECT
*</codeph> statement only expanded to primitive types even when the table contained complex-typed
columns. Support for complex types in the select list has since been added, but for backward
compatibility the behaviour that <q>*</q> expressions skip complex types has been kept as the
default. If the EXPAND_COMPLEX_TYPES query option is set to true, <q>*</q> expressions will
include complex types as well.
</p>
<p>
Note: even if EXPAND_COMPLEX_TYPES is false, complex-typed columns that are listed explicitly in
the select list (i.e. not as a <q>*</q> expression) will be included in the result.
</p>
<p><b>Type:</b>BOOLEAN</p>
<p><b>Default:</b>FALSE</p>
<p><b>Added in:</b>Impala 4.2</p>
<p conref="../shared/impala_common.xml#common/related_info"/>
<p>
<xref href="impala_complex_types.xml"/>,
</p>
</conbody>
</concept>