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

<refentry id="app-vacuumdb">
 <indexterm zone="app-vacuumdb">
  <primary>vacuumdb</primary>
 </indexterm>

 <refmeta>
  <refentrytitle><application>vacuumdb</application></refentrytitle>
  <manvolnum>1</manvolnum>
  <refmiscinfo>Application</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname id="vacuumdb">vacuumdb</refname>
  <refpurpose>garbage-collect and analyze a <productname>PostgreSQL</productname> database</refpurpose>
 </refnamediv>

 <refsynopsisdiv>
  <cmdsynopsis>
   <command>vacuumdb</command>
   <arg rep="repeat"><replaceable>connection-option</replaceable></arg>
   <arg rep="repeat"><replaceable>option</replaceable></arg>

   <arg choice="plain" rep="repeat">
    <arg choice="opt">
     <group choice="plain">
      <arg choice="plain"><option>--table</option></arg>
      <arg choice="plain"><option>-t</option></arg>
     </group>
     <replaceable>table</replaceable>
     <arg choice="opt">( <replaceable class="parameter">column</replaceable> [,...] )</arg>
    </arg>
   </arg>

   <arg choice="opt"><replaceable>dbname</replaceable></arg>
  </cmdsynopsis>

  <cmdsynopsis>
   <command>vacuumdb</command>
   <arg rep="repeat"><replaceable>connection-option</replaceable></arg>
   <arg rep="repeat"><replaceable>option</replaceable></arg>
   <group choice="plain">
    <arg choice="plain"><option>--all</option></arg>
    <arg choice="plain"><option>-a</option></arg>
   </group>
  </cmdsynopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <application>vacuumdb</application> is a utility for cleaning a
   <productname>PostgreSQL</productname> database.
   <application>vacuumdb</application> will also generate internal statistics
   used by the <productname>PostgreSQL</productname> query optimizer.
  </para>

  <para>
   <application>vacuumdb</application> is a wrapper around the SQL
   command <xref linkend="sql-vacuum"/>.
   There is no effective difference between vacuuming and analyzing
   databases via this utility and via other methods for accessing the
   server.
  </para>

 </refsect1>


 <refsect1>
  <title>Options</title>

   <para>
    <application>vacuumdb</application> accepts the following command-line arguments:
    <variablelist>
     <varlistentry>
      <term><option>-a</option></term>
      <term><option>--all</option></term>
      <listitem>
       <para>
        Vacuum all databases.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option><optional>-d</optional> <replaceable class="parameter">dbname</replaceable></option></term>
      <term><option><optional>--dbname=</optional><replaceable class="parameter">dbname</replaceable></option></term>
      <listitem>
       <para>
        Specifies the name of the database to be cleaned or analyzed.
        If this is not specified and <option>-a</option> (or
        <option>--all</option>) is not used, the database name is read
        from the environment variable <envar>PGDATABASE</envar>.  If
        that is not set, the user name specified for the connection is
        used.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-e</option></term>
      <term><option>--echo</option></term>
      <listitem>
       <para>
        Echo the commands that <application>vacuumdb</application> generates
        and sends to the server.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-f</option></term>
      <term><option>--full</option></term>
      <listitem>
       <para>
        Perform <quote>full</quote> vacuuming.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-F</option></term>
      <term><option>--freeze</option></term>
      <listitem>
       <para>
        Aggressively <quote>freeze</quote> tuples.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-j <replaceable class="parameter">njobs</replaceable></option></term>
      <term><option>--jobs=<replaceable class="parameter">njobs</replaceable></option></term>
      <listitem>
       <para>
        Execute the vacuum or analyze commands in parallel by running
        <replaceable class="parameter">njobs</replaceable>
        commands simultaneously.  This option reduces the time of the
        processing but it also increases the load on the database server.
       </para>
       <para>
        <application>vacuumdb</application> will open
        <replaceable class="parameter">njobs</replaceable> connections to the
        database, so make sure your <xref linkend="guc-max-connections"/>
        setting is high enough to accommodate all connections.
       </para>
       <para>
        Note that using this mode together with the <option>-f</option>
        (<literal>FULL</literal>) option might cause deadlock failures if
        certain system catalogs are processed in parallel.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-q</option></term>
      <term><option>--quiet</option></term>
      <listitem>
       <para>
        Do not display progress messages.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-t <replaceable class="parameter">table</replaceable> [ (<replaceable class="parameter">column</replaceable> [,...]) ]</option></term>
      <term><option>--table=<replaceable class="parameter">table</replaceable> [ (<replaceable class="parameter">column</replaceable> [,...]) ]</option></term>
      <listitem>
       <para>
        Clean or analyze <replaceable class="parameter">table</replaceable> only.
        Column names can be specified only in conjunction with
        the <option>--analyze</option> or <option>--analyze-only</option> options.
        Multiple tables can be vacuumed by writing multiple
        <option>-t</option> switches.
       </para>
       <tip>
        <para>
         If you specify columns, you probably have to escape the parentheses
         from the shell.  (See examples below.)
        </para>
       </tip>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-v</option></term>
      <term><option>--verbose</option></term>
      <listitem>
       <para>
        Print detailed information during processing.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
       <term><option>-V</option></term>
       <term><option>--version</option></term>
       <listitem>
       <para>
       Print the <application>vacuumdb</application> version and exit.
       </para>
       </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-z</option></term>
      <term><option>--analyze</option></term>
      <listitem>
       <para>
        Also calculate statistics for use by the optimizer.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-Z</option></term>
      <term><option>--analyze-only</option></term>
      <listitem>
       <para>
        Only calculate statistics for use by the optimizer (no vacuum).
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>--analyze-in-stages</option></term>
      <listitem>
       <para>
        Only calculate statistics for use by the optimizer (no vacuum),
        like <option>--analyze-only</option>.  Run several (currently three)
        stages of analyze with different configuration settings, to produce
        usable statistics faster.
       </para>

       <para>
        This option is useful to analyze a database that was newly populated
        from a restored dump or by <command>pg_upgrade</command>.  This option
        will try to create some statistics as fast as possible, to make the
        database usable, and then produce full statistics in the subsequent
        stages.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
       <term><option>-?</option></term>
       <term><option>--help</option></term>
       <listitem>
       <para>
       Show help about <application>vacuumdb</application> command line
       arguments, and exit.
       </para>
       </listitem>
     </varlistentry>

    </variablelist>
   </para>

   <para>
    <application>vacuumdb</application> also accepts
    the following command-line arguments for connection parameters:
    <variablelist>
     <varlistentry>
      <term><option>-h <replaceable class="parameter">host</replaceable></option></term>
      <term><option>--host=<replaceable class="parameter">host</replaceable></option></term>
      <listitem>
       <para>
        Specifies the host name of the machine on which the server
        is running.  If the value begins with a slash, it is used
        as the directory for the Unix domain socket.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-p <replaceable class="parameter">port</replaceable></option></term>
      <term><option>--port=<replaceable class="parameter">port</replaceable></option></term>
      <listitem>
       <para>
        Specifies the TCP port or local Unix domain socket file
        extension on which the server
        is listening for connections.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-U <replaceable class="parameter">username</replaceable></option></term>
      <term><option>--username=<replaceable class="parameter">username</replaceable></option></term>
      <listitem>
       <para>
        User name to connect as.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-w</option></term>
      <term><option>--no-password</option></term>
      <listitem>
       <para>
        Never issue a password prompt.  If the server requires
        password authentication and a password is not available by
        other means such as a <filename>.pgpass</filename> file, the
        connection attempt will fail.  This option can be useful in
        batch jobs and scripts where no user is present to enter a
        password.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>-W</option></term>
      <term><option>--password</option></term>
      <listitem>
       <para>
        Force <application>vacuumdb</application> to prompt for a
        password before connecting to a database.
       </para>

       <para>
        This option is never essential, since
        <application>vacuumdb</application> will automatically prompt
        for a password if the server demands password authentication.
        However, <application>vacuumdb</application> will waste a
        connection attempt finding out that the server wants a password.
        In some cases it is worth typing <option>-W</option> to avoid the extra
        connection attempt.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><option>--maintenance-db=<replaceable class="parameter">dbname</replaceable></option></term>
      <listitem>
       <para>
         Specifies the name of the database to connect to discover what other
         databases should be vacuumed. If not specified, the
         <literal>postgres</literal> database will be used,
         and if that does not exist, <literal>template1</literal> will be used.
       </para>
      </listitem>
     </varlistentry>
    </variablelist>
   </para>
 </refsect1>


 <refsect1>
  <title>Environment</title>

  <variablelist>
   <varlistentry>
    <term><envar>PGDATABASE</envar></term>
    <term><envar>PGHOST</envar></term>
    <term><envar>PGPORT</envar></term>
    <term><envar>PGUSER</envar></term>

    <listitem>
     <para>
      Default connection parameters
     </para>
    </listitem>
   </varlistentry>
  </variablelist>

  <para>
   This utility, like most other <productname>PostgreSQL</productname> utilities,
   also uses the environment variables supported by <application>libpq</application>
   (see <xref linkend="libpq-envars"/>).
  </para>

 </refsect1>


 <refsect1>
  <title>Diagnostics</title>

  <para>
   In case of difficulty, see <xref linkend="sql-vacuum"/>
   and <xref linkend="app-psql"/> for
   discussions of potential problems and error messages.
   The database server must be running at the
   targeted host.  Also, any default connection settings and environment
   variables used by the <application>libpq</application> front-end
   library will apply.
  </para>

 </refsect1>


 <refsect1>
  <title>Notes</title>

  <para>
   <application>vacuumdb</application> might need to connect several
   times to the <productname>PostgreSQL</productname> server, asking
   for a password each time. It is convenient to have a
   <filename>~/.pgpass</filename> file in such cases. See <xref
   linkend="libpq-pgpass"/> for more information.
  </para>
 </refsect1>

 <refsect1>
  <title>Examples</title>

   <para>
    To clean the database <literal>test</literal>:
<screen>
<prompt>$ </prompt><userinput>vacuumdb test</userinput>
</screen>
   </para>

   <para>
    To clean and analyze for the optimizer a database named
    <literal>bigdb</literal>:
<screen>
<prompt>$ </prompt><userinput>vacuumdb --analyze bigdb</userinput>
</screen>
   </para>

   <para>
    To clean a single table
    <literal>foo</literal> in a database named
    <literal>xyzzy</literal>, and analyze a single column
    <literal>bar</literal> of the table for the optimizer:
<screen>
<prompt>$ </prompt><userinput>vacuumdb --analyze --verbose --table='foo(bar)' xyzzy</userinput>
</screen></para>

 </refsect1>

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

  <simplelist type="inline">
   <member><xref linkend="sql-vacuum"/></member>
  </simplelist>
 </refsect1>

</refentry>
