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

<refentry id="sql-altertablespace">
 <indexterm zone="sql-altertablespace">
  <primary>ALTER TABLESPACE</primary>
 </indexterm>

 <refmeta>
  <refentrytitle>ALTER TABLESPACE</refentrytitle>
  <manvolnum>7</manvolnum>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>ALTER TABLESPACE</refname>
  <refpurpose>change the definition of a tablespace</refpurpose>
 </refnamediv>

 <refsynopsisdiv>
<synopsis>
ALTER TABLESPACE <replaceable>name</replaceable> RENAME TO <replaceable>new_name</replaceable>
ALTER TABLESPACE <replaceable>name</replaceable> OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER TABLESPACE <replaceable>name</replaceable> SET ( <replaceable class="parameter">tablespace_option</replaceable> = <replaceable class="parameter">value</replaceable> [, ... ] )
ALTER TABLESPACE <replaceable>name</replaceable> RESET ( <replaceable class="parameter">tablespace_option</replaceable> [, ... ] )
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>ALTER TABLESPACE</command> can be used to change the definition of
   a tablespace.
  </para>

  <para>
   You must own the tablespace to change the definition of a tablespace.
   To alter the owner, you must also be able to <literal>SET ROLE</literal>
   to the new owning role.
   (Note that superusers have these privileges automatically.)
  </para>

 </refsect1>

 <refsect1>
  <title>Parameters</title>

  <variablelist>
   <varlistentry>
    <term><replaceable class="parameter">name</replaceable></term>
    <listitem>
     <para>
      The name of an existing tablespace.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="parameter">new_name</replaceable></term>
    <listitem>
     <para>
      The new name of the tablespace.  The new name cannot
      begin with <literal>pg_</literal>, as such names
      are reserved for system tablespaces.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="parameter">new_owner</replaceable></term>
    <listitem>
     <para>
      The new owner of the tablespace.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="parameter">tablespace_option</replaceable></term>
    <listitem>
     <para>
      A tablespace parameter to be set or reset.  Currently, the only
      available parameters are <varname>seq_page_cost</varname>,
      <varname>random_page_cost</varname>, <varname>effective_io_concurrency</varname>
      and <varname>maintenance_io_concurrency</varname>.
      Setting these values for a particular tablespace will override the
      planner's usual estimate of the cost of reading pages from tables in
      that tablespace, and how many concurrent I/Os are issued, as established
      by the configuration parameters of the
      same name (see <xref linkend="guc-seq-page-cost"/>,
      <xref linkend="guc-random-page-cost"/>,
      <xref linkend="guc-effective-io-concurrency"/>,
      <xref linkend="guc-maintenance-io-concurrency"/>).  This may be useful if
      one tablespace is located on a disk which is faster or slower than the
      remainder of the I/O subsystem.
     </para>
    </listitem>
   </varlistentry>

  </variablelist>
 </refsect1>

 <refsect1>
  <title>Examples</title>

  <para>
   Rename tablespace <literal>index_space</literal> to <literal>fast_raid</literal>:
<programlisting>
ALTER TABLESPACE index_space RENAME TO fast_raid;
</programlisting>
  </para>

  <para>
   Change the owner of tablespace <literal>index_space</literal>:
<programlisting>
ALTER TABLESPACE index_space OWNER TO mary;
</programlisting></para>
 </refsect1>

 <refsect1>
  <title>Compatibility</title>

  <para>
   There is no <command>ALTER TABLESPACE</command> statement in
   the SQL standard.
  </para>
 </refsect1>

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

  <simplelist type="inline">
   <member><xref linkend="sql-createtablespace"/></member>
   <member><xref linkend="sql-droptablespace"/></member>
  </simplelist>
 </refsect1>
</refentry>