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<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept id="langref">
<title>Impala SQL Language Reference</title>
<titlealts audience="PDF"><navtitle>SQL Reference</navtitle></titlealts>
<data name="Category" value="Impala"/>
<data name="Category" value="SQL"/>
<data name="Category" value="Data Analysts"/>
<data name="Category" value="Developers"/>
<data name="Category" value="impala-shell"/>
Impala uses SQL as its query language. To protect user investment in skills development and query
design, Impala provides a high degree of compatibility with the Hive Query Language (HiveQL):
Because Impala uses the same metadata store as Hive to record information about table structure and
properties, Impala can access tables defined through the native Impala <codeph>CREATE TABLE</codeph>
command, or tables created using the Hive data definition language (DDL).
Impala supports data manipulation (DML) statements similar to the DML component of HiveQL.
Impala provides many <xref href="impala_functions.xml#builtins">built-in functions</xref> with the same
names and parameter types as their HiveQL equivalents.
Impala supports most of the same <xref href="impala_langref_sql.xml#langref_sql">statements and
clauses</xref> as HiveQL, including, but not limited to <codeph>JOIN</codeph>, <codeph>AGGREGATE</codeph>,
<codeph>DISTINCT</codeph>, <codeph>UNION ALL</codeph>, <codeph>ORDER BY</codeph>, <codeph>LIMIT</codeph> and
(uncorrelated) subquery in the <codeph>FROM</codeph> clause. Impala also supports <codeph>INSERT
INTO</codeph> and <codeph>INSERT OVERWRITE</codeph>.
Impala supports data types with the same names and semantics as the equivalent Hive data types:
<codeph>STRING</codeph>, <codeph>TINYINT</codeph>, <codeph>SMALLINT</codeph>, <codeph>INT</codeph>,
<codeph>BIGINT</codeph>, <codeph>FLOAT</codeph>, <codeph>DOUBLE</codeph>, <codeph>BOOLEAN</codeph>,
<codeph>STRING</codeph>, <codeph>TIMESTAMP</codeph>.
For full details about Impala SQL syntax and semantics, see
<xref href="impala_langref_sql.xml#langref_sql"/>.
Most HiveQL <codeph>SELECT</codeph> and <codeph>INSERT</codeph> statements run unmodified with Impala. For
information about Hive syntax not available in Impala, see
<xref href="impala_langref_unsupported.xml#langref_hiveql_delta"/>.
For a list of the built-in functions available in Impala queries, see
<xref href="impala_functions.xml#builtins"/>.
<p outputclass="toc"/>