<!--
doc/src/sgml/ref/alter_foreign_data_wrapper.sgml
PostgreSQL documentation
-->

<refentry id="sql-alterforeigndatawrapper">
 <indexterm zone="sql-alterforeigndatawrapper">
  <primary>ALTER FOREIGN DATA WRAPPER</primary>
 </indexterm>

 <refmeta>
  <refentrytitle>ALTER FOREIGN DATA WRAPPER</refentrytitle>
  <manvolnum>7</manvolnum>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>ALTER FOREIGN DATA WRAPPER</refname>
  <refpurpose>change the definition of a foreign-data wrapper</refpurpose>
 </refnamediv>

 <refsynopsisdiv>
<synopsis>
ALTER FOREIGN DATA WRAPPER <replaceable class="parameter">name</replaceable>
    [ HANDLER <replaceable class="parameter">handler_function</replaceable> | NO HANDLER ]
    [ VALIDATOR <replaceable class="parameter">validator_function</replaceable> | NO VALIDATOR ]
    [ OPTIONS ( [ ADD | SET | DROP ] <replaceable class="parameter">option</replaceable> ['<replaceable class="parameter">value</replaceable>'] [, ... ]) ]
ALTER FOREIGN DATA WRAPPER <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER FOREIGN DATA WRAPPER <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>ALTER FOREIGN DATA WRAPPER</command> changes the
   definition of a foreign-data wrapper.  The first form of the
   command changes the support functions or the generic options of the
   foreign-data wrapper (at least one clause is required).  The second
   form changes the owner of the foreign-data wrapper.
  </para>

  <para>
   Only superusers can alter foreign-data wrappers.  Additionally,
   only superusers can own foreign-data wrappers.
  </para>
 </refsect1>

 <refsect1>
  <title>Parameters</title>

  <variablelist>
   <varlistentry>
    <term><replaceable class="parameter">name</replaceable></term>
    <listitem>
     <para>
      The name of an existing foreign-data wrapper.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>HANDLER <replaceable class="parameter">handler_function</replaceable></literal></term>
    <listitem>
     <para>
      Specifies a new handler function for the foreign-data wrapper.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>NO HANDLER</literal></term>
    <listitem>
     <para>
      This is used to specify that the foreign-data wrapper should no
      longer have a handler function.
     </para>
     <para>
      Note that foreign tables that use a foreign-data wrapper with no
      handler cannot be accessed.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>VALIDATOR <replaceable class="parameter">validator_function</replaceable></literal></term>
    <listitem>
     <para>
      Specifies a new validator function for the foreign-data wrapper.
     </para>

     <para>
      Note that it is