doc/src/sgml/ref/alter_foreign_data_wrapper.sgml

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   2 doc/src/sgml/ref/alter_foreign_data_wrapper.sgml
   3 PostgreSQL documentation
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   5
   6 <refentry id="sql-alterforeigndatawrapper">
   7  <indexterm zone="sql-alterforeigndatawrapper">
   8   <primary>ALTER FOREIGN DATA WRAPPER</primary>
   9  </indexterm>
  10
  11  <refmeta>
  12   <refentrytitle>ALTER FOREIGN DATA WRAPPER</refentrytitle>
  13   <manvolnum>7</manvolnum>
  14   <refmiscinfo>SQL - Language Statements</refmiscinfo>
  15  </refmeta>
  16
  17  <refnamediv>
  18   <refname>ALTER FOREIGN DATA WRAPPER</refname>
  19   <refpurpose>change the definition of a foreign-data wrapper</refpurpose>
  20  </refnamediv>
  21
  22  <refsynopsisdiv>
  23 <synopsis>
  24 ALTER FOREIGN DATA WRAPPER <replaceable class="parameter">name</replaceable>
  25     [ HANDLER <replaceable class="parameter">handler_function</replaceable> | NO HANDLER ]
  26     [ VALIDATOR <replaceable class="parameter">validator_function</replaceable> | NO VALIDATOR ]
  27     [ OPTIONS ( [ ADD | SET | DROP ] <replaceable class="parameter">option</replaceable> ['<replaceable class="parameter">value</replaceable>'] [, ... ]) ]
  28 ALTER FOREIGN DATA WRAPPER <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
  29 ALTER FOREIGN DATA WRAPPER <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
  30 </synopsis>
  31  </refsynopsisdiv>
  32
  33  <refsect1>
  34   <title>Description</title>
  35
  36   <para>
  37    <command>ALTER FOREIGN DATA WRAPPER</command> changes the
  38    definition of a foreign-data wrapper.  The first form of the
  39    command changes the support functions or the generic options of the
  40    foreign-data wrapper (at least one clause is required).  The second
  41    form changes the owner of the foreign-data wrapper.
  42   </para>
  43
  44   <para>
  45    Only superusers can alter foreign-data wrappers.  Additionally,
  46    only superusers can own foreign-data wrappers.
  47   </para>
  48  </refsect1>
  49
  50  <refsect1>
  51   <title>Parameters</title>
  52
  53   <variablelist>
  54    <varlistentry>
  55     <term><replaceable class="parameter">name</replaceable></term>
  56     <listitem>
  57      <para>
  58       The name of an existing foreign-data wrapper.
  59      </para>
  60     </listitem>
  61    </varlistentry>
  62
  63    <varlistentry>
  64     <term><literal>HANDLER <replaceable class="parameter">handler_function</replaceable></literal></term>
  65     <listitem>
  66      <para>
  67       Specifies a new handler function for the foreign-data wrapper.
  68      </para>
  69     </listitem>
  70    </varlistentry>
  71
  72    <varlistentry>
  73     <term><literal>NO HANDLER</literal></term>
  74     <listitem>
  75      <para>
  76       This is used to specify that the foreign-data wrapper should no
  77       longer have a handler function.
  78      </para>
  79      <para>
  80       Note that foreign tables that use a foreign-data wrapper with no
  81       handler cannot be accessed.
  82      </para>
  83     </listitem>
  84    </varlistentry>
  85
  86    <varlistentry>
  87     <term><literal>VALIDATOR <replaceable class="parameter">validator_function</replaceable></literal></term>
  88     <listitem>
  89      <para>
  90       Specifies a new validator function for the foreign-data wrapper.
  91      </para>
  92
  93      <para>
  94       Note that it is possible that pre-existing options of the foreign-data
  95       wrapper, or of dependent servers, user mappings, or foreign tables, are
  96       invalid according to the new validator.  <productname>PostgreSQL</productname> does
  97       not check for this.  It is up to the user to make sure that these
  98       options are correct before using the modified foreign-data wrapper.
  99       However, any options specified in this <command>ALTER FOREIGN DATA
 100       WRAPPER</command> command will be checked using the new validator.
 101      </para>
 102     </listitem>
 103    </varlistentry>
 104
 105    <varlistentry>
 106     <term><literal>NO VALIDATOR</literal></term>
 107     <listitem>
 108      <para>
 109       This is used to specify that the foreign-data wrapper should no
 110       longer have a validator function.
 111      </para>
 112     </listitem>
 113    </varlistentry>
 114
 115    <varlistentry>
 116     <term><literal>OPTIONS ( [ ADD | SET | DROP ] <replaceable class="parameter">option</replaceable> ['<replaceable class="parameter">value</replaceable>'] [, ... ] )</literal></term>
 117     <listitem>
 118      <para>
 119       Change options for the foreign-data
 120       wrapper.  <literal>ADD</literal>, <literal>SET</literal>, and <literal>DROP</literal>
 121       specify the action to be performed.  <literal>ADD</literal> is assumed
 122       if no operation is explicitly specified.  Option names must be
 123       unique; names and values are also validated using the foreign
 124       data wrapper's validator function, if any.
 125      </para>
 126     </listitem>
 127    </varlistentry>
 128
 129    <varlistentry>
 130     <term><replaceable class="parameter">new_owner</replaceable></term>
 131     <listitem>
 132      <para>
 133       The user name of the new owner of the foreign-data wrapper.
 134      </para>
 135     </listitem>
 136    </varlistentry>
 137
 138    <varlistentry>
 139     <term><replaceable class="parameter">new_name</replaceable></term>
 140     <listitem>
 141      <para>
 142       The new name for the foreign-data wrapper.
 143      </para>
 144     </listitem>
 145    </varlistentry>
 146   </variablelist>
 147  </refsect1>
 148
 149  <refsect1>
 150   <title>Examples</title>
 151
 152   <para>
 153    Change a foreign-data wrapper <literal>dbi</literal>, add
 154    option <literal>foo</literal>, drop <literal>bar</literal>:
 155 <programlisting>
 156 ALTER FOREIGN DATA WRAPPER dbi OPTIONS (ADD foo '1', DROP 'bar');
 157 </programlisting>
 158   </para>
 159
 160   <para>
 161    Change the foreign-data wrapper <literal>dbi</literal> validator
 162    to <literal>bob.myvalidator</literal>:
 163 <programlisting>
 164 ALTER FOREIGN DATA WRAPPER dbi VALIDATOR bob.myvalidator;
 165 </programlisting></para>
 166  </refsect1>
 167
 168  <refsect1>
 169   <title>Compatibility</title>
 170
 171   <para>
 172    <command>ALTER FOREIGN DATA WRAPPER</command> conforms to ISO/IEC
 173    9075-9 (SQL/MED), except that the <literal>HANDLER</literal>,
 174    <literal>VALIDATOR</literal>, <literal>OWNER TO</literal>, and <literal>RENAME</literal>
 175    clauses are extensions.
 176   </para>
 177  </refsect1>
 178
 179  <refsect1>
 180   <title>See Also</title>
 181
 182   <simplelist type="inline">
 183    <member><xref linkend="sql-createforeigndatawrapper"/></member>
 184    <member><xref linkend="sql-dropforeigndatawrapper"/></member>
 185   </simplelist>
 186  </refsect1>
 187
 188 </refentry>