postgres/doc/src/sgml/ref/create_tablespace.sgml

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doc/src/sgml/ref/create_tablespace.sgml
PostgreSQL documentation
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<refentry id="SQL-CREATETABLESPACE">
 <indexterm zone="sql-createtablespace">
  <primary>CREATE TABLESPACE</primary>
 </indexterm>

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

 <refnamediv>
  <refname>CREATE TABLESPACE</refname>
  <refpurpose>define a new tablespace</refpurpose>
 </refnamediv>

 <refsynopsisdiv>
<synopsis>
CREATE TABLESPACE <replaceable class="parameter">tablespace_name</replaceable>
    [ OWNER <replaceable class="parameter">user_name</replaceable> ]
    LOCATION '<replaceable class="parameter">directory</replaceable>'
    [ WITH ( <replaceable class="PARAMETER">tablespace_option</replaceable> = <replaceable class="PARAMETER">value</replaceable> [, ... ] ) ]
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>CREATE TABLESPACE</command> registers a new cluster-wide
   tablespace.  The tablespace name must be distinct from the name of any
   existing tablespace in the database cluster.
  </para>

  <para>
   A tablespace allows superusers to define an alternative location on
   the file system where the data files containing database objects
   (such as tables and indexes) can reside.
  </para>

  <para>
   A user with appropriate privileges can pass
   <replaceable class="parameter">tablespace_name</> to
   <command>CREATE DATABASE</>, <command>CREATE TABLE</>,
   <command>CREATE INDEX</> or <command>ADD CONSTRAINT</> to have the data
   files for these objects stored within the specified tablespace.
  </para>

  <warning>
   <para>
    A tablespace cannot be used independently of the cluster in which it
    is defined;  see <xref linkend="manage-ag-tablespaces"/>.
   </para>
  </warning>

 </refsect1>

 <refsect1>
  <title>Parameters</title>

    <variablelist>
     <varlistentry>
      <term><replaceable class="parameter">tablespace_name</replaceable></term>
      <listitem>
       <para>
        The name of a tablespace to be created.  The name cannot
        begin with <literal>pg_</literal>, as such names
        are reserved for system tablespaces.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><replaceable class="parameter">user_name</replaceable></term>
      <listitem>
       <para>
        The name of the user who will own the tablespace.  If omitted,
        defaults to the user executing the command.  Only superusers
        can create tablespaces, but they can assign ownership of tablespaces
        to non-superusers.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><replaceable class="parameter">directory</replaceable></term>
      <listitem>
       <para>
        The directory that will be used for the tablespace. The directory
        should be empty and must be owned by the
        <productname>PostgreSQL</> system user.  The directory must be
        specified by an absolute path name.
       </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</> and
        <varname>random_page_cost</>.  Setting either value for a particular
        tablespace will override the planner's usual estimate of the cost of
        reading pages from tables in that tablespace, as established by
        the configuration parameters of the same name (see
        <xref linkend="guc-seq-page-cost">,
        <xref linkend="guc-random-page-cost">).  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>Notes</title>

  <para>
   Tablespaces are only supported on systems that support symbolic links.
  </para>

   <para>
    <command>CREATE TABLESPACE</> cannot be executed inside a transaction
    block.
   </para>
 </refsect1>

 <refsect1>
  <title>Examples</title>

  <para>
   Create a tablespace <literal>dbspace</> at <literal>/data/dbs</>:
<programlisting>
CREATE TABLESPACE dbspace LOCATION '/data/dbs';
</programlisting>
  </para>

  <para>
   Create a tablespace <literal>indexspace</> at <literal>/data/indexes</>
   owned by user <literal>genevieve</>:
<programlisting>
CREATE TABLESPACE indexspace OWNER genevieve LOCATION '/data/indexes';
</programlisting></para>
 </refsect1>

 <refsect1>
  <title>Compatibility</title>

  <para>
   <command>CREATE TABLESPACE</command> is a <productname>PostgreSQL</>
   extension.
  </para>
 </refsect1>

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

  <simplelist type="inline">
   <member><xref linkend="sql-createdatabase"></member>
   <member><xref linkend="sql-createtable"></member>
   <member><xref linkend="sql-createindex"></member>
   <member><xref linkend="sql-droptablespace"></member>
   <member><xref linkend="sql-altertablespace"></member>
  </simplelist>
 </refsect1>

</refentry>