postgres/doc/src/sgml/adminpack.sgml

<!-- doc/src/sgml/adminpack.sgml -->

<sect1 id="adminpack" xreflabel="adminpack">
 <title>adminpack</title>

 <indexterm zone="adminpack">
  <primary>adminpack</primary>
 </indexterm>

 <para>
  <filename>adminpack</filename> provides a number of support functions which
  <application>pgAdmin</application> and other administration and management tools can
  use to provide additional functionality, such as remote management
  of server log files.
  Use of all these functions is only allowed to the superuser by default but may be
  allowed to other users by using the <command>GRANT</command> command.
 </para>

 <para>
  The functions shown in <xref linkend="functions-adminpack-table"/> provide
  write access to files on the machine hosting the server.  (See also the
  functions in <xref linkend="functions-admin-genfile-table"/>, which
  provide read-only access.)
  Only files within the database cluster directory can be accessed, unless the
  user is a superuser or given privileges of one of the
  <literal>pg_read_server_files</literal> or
  <literal>pg_write_server_files</literal> roles, as appropriate for the
  function, but either a relative or absolute path is allowable.
 </para>

 <table id="functions-adminpack-table">
  <title><filename>adminpack</filename> Functions</title>
    <tgroup cols="1">
     <thead>
      <row>
       <entry role="func_table_entry"><para role="func_signature">
        Function
       </para>
       <para>
        Description
       </para></entry>
      </row>
     </thead>

     <tbody>
      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <function>pg_catalog.pg_file_write</function> ( <parameter>filename</parameter> <type>text</type>, <parameter>data</parameter> <type>text</type>, <parameter>append</parameter> <type>boolean</type> )
        <returnvalue>bigint</returnvalue>
       </para>
       <para>
        Writes, or appends to, a text file.
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <function>pg_catalog.pg_file_sync</function> ( <parameter>filename</parameter> <type>text</type> )
        <returnvalue>void</returnvalue>
       </para>
       <para>
        Flushes a file or directory to disk.
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <function>pg_catalog.pg_file_rename</function> ( <parameter>oldname</parameter> <type>text</type>, <parameter>newname</parameter> <type>text</type> <optional>, <parameter>archivename</parameter> <type>text</type> </optional> )
        <returnvalue>boolean</returnvalue>
       </para>
       <para>
        Renames a file.
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <function>pg_catalog.pg_file_unlink</function> ( <parameter>filename</parameter> <type>text</type> )
        <returnvalue>boolean</returnvalue>
       </para>
       <para>
        Removes a file.
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <function>pg_catalog.pg_logdir_ls</function> ()
        <returnvalue>setof record</returnvalue>
       </para>
       <para>
        Lists the log files in the <varname>log_directory</varname> directory.
       </para></entry>
      </row>
     </tbody>
  </tgroup>
 </table>

 <indexterm>
  <primary>pg_file_write</primary>
 </indexterm>
 <para>
  <function>pg_file_write</function> writes the specified <parameter>data</parameter> into
  the file named by <parameter>filename</parameter>.  If <parameter>append</parameter> is
  false, the file must not already exist.  If <parameter>append</parameter> is true,
  the file can already exist, and will be appended to if so.
  Returns the number of bytes written.
 </para>

 <indexterm>
  <primary>pg_file_sync</primary>
 </indexterm>
 <para>
  <function>pg_file_sync</function> fsyncs the specified file or directory
  named by <parameter>filename</parameter>.  An error is thrown
  on failure (e.g., the specified file is not present). Note that
  <xref linkend="guc-data-sync-retry"/> has no effect on this function,
  and therefore a PANIC-level error will not be raised even on failure to
  flush database files.
 </para>

 <indexterm>
  <primary>pg_file_rename</primary>
 </indexterm>
 <para>
  <function>pg_file_rename</function> renames a file.  If <parameter>archivename</parameter>
  is omitted or NULL, it simply renames <parameter>oldname</parameter>
  to <parameter>newname</parameter> (which must not already exist).
  If <parameter>archivename</parameter> is provided, it first
  renames <parameter>newname</parameter> to <parameter>archivename</parameter> (which must
  not already exist), and then renames <parameter>oldname</parameter>
  to <parameter>newname</parameter>.  In event of failure of the second rename step,
  it will try to rename <parameter>archivename</parameter> back
  to <parameter>newname</parameter> before reporting the error.
  Returns true on success, false if the source file(s) are not present or
  not writable; other cases throw errors.
 </para>

 <indexterm>
  <primary>pg_file_unlink</primary>
 </indexterm>
 <para>
  <function>pg_file_unlink</function> removes the specified file.
  Returns true on success, false if the specified file is not present
  or the <function>unlink()</function> call fails; other cases throw errors.
 </para>

 <indexterm>
  <primary>pg_logdir_ls</primary>
 </indexterm>
 <para>
  <function>pg_logdir_ls</function> returns the start timestamps and path
  names of all the log files in the <xref linkend="guc-log-directory"/>
  directory.  The <xref linkend="guc-log-filename"/> parameter must have its
  default setting (<literal>postgresql-%Y-%m-%d_%H%M%S.log</literal>) to use this
  function.
 </para>

</sect1>