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doc/src/sgml/ref/refresh_materialized_view.sgml
PostgreSQL documentation
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<refentry id="SQL-REFRESHMATERIALIZEDVIEW">
 <refmeta>
  <refentrytitle>REFRESH MATERIALIZED VIEW</refentrytitle>
  <manvolnum>7</manvolnum>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>REFRESH MATERIALIZED VIEW</refname>
  <refpurpose>replace the contents of a materialized view</refpurpose>
 </refnamediv>

 <indexterm zone="sql-refreshmaterializedview">
  <primary>REFRESH MATERIALIZED VIEW</primary>
 </indexterm>

 <refsynopsisdiv>
<synopsis>
REFRESH MATERIALIZED VIEW <replaceable class="PARAMETER">name</replaceable>
    [ WITH [ NO ] DATA ]
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>REFRESH MATERIALIZED VIEW</command> completely replaces the
   contents of a materialized view.  The old contents are discarded.  If
   <literal>WITH DATA</literal> is specified (or defaults) the backing query
   is executed to provide the new data, and the materialized view is left in a
   scannable state.  If <literal>WITH NO DATA</literal> is specified no new
   data is generated and the materialized view is left in an unscannable
   state.
  </para>
 </refsect1>

 <refsect1>
  <title>Parameters</title>

  <variablelist>
   <varlistentry>
    <term><replaceable class="PARAMETER">name</replaceable></term>
    <listitem>
     <para>
      The name (optionally schema-qualified) of the materialized view to
      refresh.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1>
  <title>Notes</title>

  <para>
   While the default index for future
   <xref linkend="SQL-CLUSTER">
   operations is retained, <command>REFRESH MATERIALIZED VIEW</> does not
   order the generated rows based on this property. If you want the data
   to be ordered upon generation, you must use an <literal>ORDER BY</>
   clause in the backing query.
  </para>
 </refsect1>

 <refsect1>
  <title>Examples</title>

  <para>
   This command will replace the contents of the materialized view called
   <literal>order_summary</literal> using the query from the materialized
   view's definition, and leave it in a scannable state:
<programlisting>
REFRESH MATERIALIZED VIEW order_summary;
</programlisting>
  </para>

  <para>
   This command will free storage associated with the materialized view
   <literal>annual_statistics_basis</literal> and leave it in an unscannable
   state:
<programlisting>
REFRESH MATERIALIZED VIEW annual_statistics_basis WITH NO DATA;
</programlisting></para>
 </refsect1>

 <refsect1>
  <title>Compatibility</title>

  <para>
   <command>REFRESH MATERIALIZED VIEW</command> is a
   <productname>PostgreSQL</productname> extension.
  </para>
 </refsect1>

 <refsect1>
  <title>See Also</title>

  <simplelist type="inline">
   <member><xref linkend="sql-creatematerializedview"></member>
   <member><xref linkend="sql-altermaterializedview"></member>
   <member><xref linkend="sql-dropmaterializedview"></member>
  </simplelist>
 </refsect1>

</refentry>
