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

<refentry id="sql-altersubscription">
 <indexterm zone="sql-altersubscription">
  <primary>ALTER SUBSCRIPTION</primary>
 </indexterm>

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

 <refnamediv>
  <refname>ALTER SUBSCRIPTION</refname>
  <refpurpose>change the definition of a subscription</refpurpose>
 </refnamediv>

 <refsynopsisdiv>
<synopsis>
ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> CONNECTION '<replaceable>conninfo</replaceable>'
ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> SET PUBLICATION <replaceable class="parameter">publication_name</replaceable> [, ...] [ WITH ( <replaceable class="parameter">publication_option</replaceable> [= <replaceable class="parameter">value</replaceable>] [, ... ] ) ]
ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> ADD PUBLICATION <replaceable class="parameter">publication_name</replaceable> [, ...] [ WITH ( <replaceable class="parameter">publication_option</replaceable> [= <replaceable class="parameter">value</replaceable>] [, ... ] ) ]
ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> DROP PUBLICATION <replaceable class="parameter">publication_name</replaceable> [, ...] [ WITH ( <replaceable class="parameter">publication_option</replaceable> [= <replaceable class="parameter">value</replaceable>] [, ... ] ) ]
ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> REFRESH PUBLICATION [ WITH ( <replaceable class="parameter">refresh_option</replaceable> [= <replaceable class="parameter">value</replaceable>] [, ... ] ) ]
ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> ENABLE
ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> DISABLE
ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> SET ( <replaceable class="parameter">subscription_parameter</replaceable> [= <replaceable class="parameter">value</replaceable>] [, ... ] )
ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> SKIP ( <replaceable class="parameter">skip_option</replaceable> = <replaceable class="parameter">value</replaceable> )
ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>ALTER SUBSCRIPTION</command> can change most of the subscription
   properties that can be specified
   in <xref linkend="sql-createsubscription"/>.
  </para>

  <para>
   You must own the subscription to use <command>ALTER SUBSCRIPTION</command>.
   To rename a subscription or alter the owner, you must have
   <literal>CREATE</literal> permission on the database. In addition,
   to alter the owner, you must be able to <literal>SET ROLE</literal> to the
   new owning role. If the subscription has
   <literal>password_required=false</literal>, only superusers can modify it.
  </para>

  <para>
   When refreshing a publication we remove the relations that are no longer
   part of the publication and we also remove the table synchronization slots
   if there are any. It is necessary to remove these slots so that the resources
   allocated for the subscription on the remote host are released. If due to
   network breakdown or some other error, <productname>PostgreSQL</productname>
   is unable to remove the slots, an error will be reported. To proceed in this
   situation, the user either needs to retry the operation or disassociate the
   slot from the subscription and drop the subscription as explained in
   <xref linkend="sql-dropsubscription"/>.
  </para>

  <para>
   Commands <command>ALTER SUBSCRIPTION ... REFRESH PUBLICATION</command> and
   <command>ALTER SUBSCRIPTION ... {SET|ADD|DROP} PUBLICATION ...</command>
   with <literal>refresh</literal> option as <literal>true</literal> cannot be
   executed inside a transaction block.

   These commands also cannot be executed when the subscription has
   <link linkend="sql-createsubscription-with-two-phase"><literal>two_phase</literal></link>
   commit enabled, unless
   <link linkend="sql-createsubscription-with-copy-data"><literal>copy_data</literal></link>
   is <literal>false</literal>. See column <structfield>subtwophasestate</structfield>
   of <link linkend="catalog-pg-subscription"><structname>pg_subscription</structname></link>
   to know the actual two-phase state.
  </para>
 </refsect1>

 <refsect1>
  <title>Parameters</title>

  <variablelist>
   <varlistentry>
    <term><replaceable class="parameter">name</replaceable></term>
    <listitem>
     <para>
      The name of a subscription whose properties are to be altered.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>CONNECTION '<replaceable class="parameter">conninfo</replaceable>'</literal></term>
    <listitem>
     <para>
      This clause replaces the connection string originally set by
      <xref linkend="sql-createsubscription"/>.  See there for more
      information.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>SET PUBLICATION <replaceable class="parameter">publication_name</replaceable></literal></term>
    <term><literal>ADD PUBLICATION <replaceable class="parameter">publication_name</replaceable></literal></term>
    <term><literal>DROP PUBLICATION <replaceable class="parameter">publication_name</replaceable></literal></term>
    <listitem>
     <para>
      These forms change the list of subscribed publications.
      <literal>SET</literal>
      replaces the entire list of publications with a new list,
      <literal>ADD</literal> adds additional publications to the list of
      publications, and <literal>DROP</literal> removes the publications from
      the list of publications.  We allow non-existent publications to be
      specified in <literal>ADD</literal> and <literal>SET</literal> variants
      so that users can add those later.  See <xref linkend="sql-createsubscription"/>
      for more information.  By default, this command will also act like
      <literal>REFRESH PUBLICATION</literal>.
     </para>

     <para>
      <replaceable>publication_option</replaceable> specifies additional
      options for this operation.  The supported options are:

      <variablelist>
       <varlistentry>
        <term><literal>refresh</literal> (<type>boolean</type>)</term>
        <listitem>
         <para>
          When false, the command will not try to refresh table information.
          <literal>REFRESH PUBLICATION</literal> should then be executed separately.
          The default is <literal>true</literal>.
         </para>
        </listitem>
       </varlistentry>
      </variablelist>

      Additionally, the options described under
      <literal>REFRESH PUBLICATION</literal> may be specified, to control the
      implicit refresh operation.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>REFRESH PUBLICATION</literal></term>
    <listitem>
     <para>
      Fetch missing table information from publisher.  This will start
      replication of tables that were added to the subscribed-to publications
      since <command>CREATE SUBSCRIPTION</command> or
      the last invocation of <command>REFRESH PUBLICATION</command>.
     </para>

     <para>
      <replaceable>refresh_option</replaceable> specifies additional options for the
      refresh operation.  The supported options are:

      <variablelist>
       <varlistentry>
        <term><literal>copy_data</literal> (<type>boolean</type>)</term>
        <listitem>
         <para>
          Specifies whether to copy pre-existing data in the publications
          that are being subscribed to when the replication starts.
          The default is <literal>true</literal>.
         </para>
         <para>
          Previously subscribed tables are not copied, even if a table's row
          filter <literal>WHERE</literal> clause has since been modified.
         </para>
         <para>
          See <xref linkend="sql-createsubscription-notes"/> for details of
          how <literal>copy_data = true</literal> can interact with the
          <link linkend="sql-createsubscription-with-origin"><literal>origin</literal></link>
          parameter.
         </para>
         <para>
          See the
          <link linkend="sql-createsubscription-with-binary"><literal>binary</literal></link>
          parameter of <command>CREATE SUBSCRIPTION</command> for details about
          copying pre-existing data in binary format.
         </para>
        </listitem>
       </varlistentry>
      </variablelist></para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>ENABLE</literal></term>
    <listitem>
     <para>
      Enables a previously disabled subscription, starting the logical
      replication worker at the end of the transaction.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>DISABLE</literal></term>
    <listitem>
     <para>
      Disables a running subscription, stopping the logical replication
      worker at the end of the transaction.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>SET ( <replaceable class="parameter">subscription_parameter</replaceable> [= <replaceable class="parameter">value</replaceable>] [, ... ] )</literal></term>
    <listitem>
     <para>
      This clause alters parameters originally set by
      <xref linkend="sql-createsubscription"/>.  See there for more
      information.  The parameters that can be altered are
      <link linkend="sql-createsubscription-with-slot-name"><literal>slot_name</literal></link>,
      <link linkend="sql-createsubscription-with-synchronous-commit"><literal>synchronous_commit</literal></link>,
      <link linkend="sql-createsubscription-with-binary"><literal>binary</literal></link>,
      <link linkend="sql-createsubscription-with-streaming"><literal>streaming</literal></link>,
      <link linkend="sql-createsubscription-with-disable-on-error"><literal>disable_on_error</literal></link>,
      <link linkend="sql-createsubscription-with-password-required"><literal>password_required</literal></link>,
      <link linkend="sql-createsubscription-with-run-as-owner"><literal>run_as_owner</literal></link>, and
      <link linkend="sql-createsubscription-with-origin"><literal>origin</literal></link>.
      Only a superuser can set <literal>password_required = false</literal>.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>SKIP ( <replaceable class="parameter">skip_option</replaceable> = <replaceable class="parameter">value</replaceable> )</literal></term>
    <listitem>
     <para>
      Skips applying all changes of the remote transaction.  If incoming data
      violates any constraints, logical replication will stop until it is
      resolved.  By using the <command>ALTER SUBSCRIPTION ... SKIP</command> command,
      the logical replication worker skips all data modification changes within
      the transaction.  This option has no effect on the transactions that are
      already prepared by enabling
      <link linkend="sql-createsubscription-with-two-phase"><literal>two_phase</literal></link>
      on the subscriber.
      After the logical replication worker successfully skips the transaction or
      finishes a transaction, the LSN (stored in
      <structname>pg_subscription</structname>.<structfield>subskiplsn</structfield>)
      is cleared.  See <xref linkend="logical-replication-conflicts"/> for
      the details of logical replication conflicts.
     </para>

     <para>
      <replaceable>skip_option</replaceable> specifies options for this operation.
      The supported option is:

      <variablelist>
       <varlistentry>
        <term><literal>lsn</literal> (<type>pg_lsn</type>)</term>
        <listitem>
         <para>
          Specifies the finish LSN of the remote transaction whose changes
          are to be skipped by the logical replication worker.  The finish LSN
          is the LSN at which the transaction is either committed or prepared.
          Skipping individual subtransactions is not supported.  Setting
          <literal>NONE</literal> resets the LSN.
         </para>
        </listitem>
       </varlistentry>
      </variablelist></para>
    </listitem>
   </varlistentry>

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

   <varlistentry>
    <term><replaceable class="parameter">new_name</replaceable></term>
    <listitem>
     <para>
      The new name for the subscription.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>

  <para>
   When specifying a parameter of type <type>boolean</type>, the
   <literal>=</literal> <replaceable class="parameter">value</replaceable>
   part can be omitted, which is equivalent to
   specifying <literal>TRUE</literal>.
  </para>
 </refsect1>

 <refsect1>
  <title>Examples</title>

  <para>
   Change the publication subscribed by a subscription to
   <literal>insert_only</literal>:
<programlisting>
ALTER SUBSCRIPTION mysub SET PUBLICATION insert_only;
</programlisting>
  </para>

  <para>
   Disable (stop) the subscription:
<programlisting>
ALTER SUBSCRIPTION mysub DISABLE;
</programlisting></para>
 </refsect1>

 <refsect1>
  <title>Compatibility</title>

  <para>
   <command>ALTER SUBSCRIPTION</command> is a <productname>PostgreSQL</productname>
   extension.
  </para>
 </refsect1>

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

  <simplelist type="inline">
   <member><xref linkend="sql-createsubscription"/></member>
   <member><xref linkend="sql-dropsubscription"/></member>
   <member><xref linkend="sql-createpublication"/></member>
   <member><xref linkend="sql-alterpublication"/></member>
  </simplelist>
 </refsect1>
</refentry>
