postgresql/doc/src/sgml/ref/drop_subscription.sgml

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<!--
doc/src/sgml/ref/drop_subscription.sgml
PostgreSQL documentation
-->
<refentry id="sql-dropsubscription">
<indexterm zone="sql-dropsubscription">
<primary>DROP SUBSCRIPTION</primary>
</indexterm>
<refmeta>
<refentrytitle>DROP SUBSCRIPTION</refentrytitle>
<manvolnum>7</manvolnum>
<refmiscinfo>SQL - Language Statements</refmiscinfo>
</refmeta>
<refnamediv>
<refname>DROP SUBSCRIPTION</refname>
<refpurpose>remove a subscription</refpurpose>
</refnamediv>
<refsynopsisdiv>
<synopsis>
DROP SUBSCRIPTION [ IF EXISTS ] <replaceable class="parameter">name</replaceable> [ CASCADE | RESTRICT ]
</synopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
<command>DROP SUBSCRIPTION</command> removes a subscription from the
database cluster.
</para>
<para>
A subscription can only be dropped by a superuser.
</para>
<para>
<command>DROP SUBSCRIPTION</command> cannot be executed inside a
transaction block if the subscription is associated with a replication
slot. (You can use <command>ALTER SUBSCRIPTION</command> to unset the
slot.)
</para>
</refsect1>
<refsect1>
<title>Parameters</title>
<variablelist>
<varlistentry>
<term><replaceable class="parameter">name</replaceable></term>
<listitem>
<para>
The name of a subscription to be dropped.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>CASCADE</literal></term>
<term><literal>RESTRICT</literal></term>
<listitem>
<para>
These key words do not have any effect, since there are no dependencies
on subscriptions.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Notes</title>
<para>
When dropping a subscription that is associated with a replication slot on
the remote host (the normal state), <command>DROP SUBSCRIPTION</command>
will connect to the remote host and try to drop the replication slot (and
any remaining table synchronization slots) as
part of its operation. This is necessary so that the resources allocated
for the subscription on the remote host are released. If this fails,
either because the remote host is not reachable or because the remote
replication slot cannot be dropped or does not exist or never existed,
the <command>DROP SUBSCRIPTION</command> command will fail. To proceed in
this situation, disassociate the subscription from the replication slot by
executing <literal>ALTER SUBSCRIPTION ... SET (slot_name = NONE)</literal>.
After that, <command>DROP SUBSCRIPTION</command> will no longer attempt any
actions on a remote host. Note that if the remote replication slot still
exists, it (and any related table synchronization slots) should then be
dropped manually; otherwise it/they will continue to
reserve WAL and might eventually cause the disk to fill up. See
also <xref linkend="logical-replication-subscription-slot"/>.
</para>
<para>
If a subscription is associated with a replication slot, then <command>DROP
SUBSCRIPTION</command> cannot be executed inside a transaction block.
</para>
</refsect1>
<refsect1>
<title>Examples</title>
<para>
Drop a subscription:
<programlisting>
DROP SUBSCRIPTION mysub;
</programlisting></para>
</refsect1>
<refsect1>
<title>Compatibility</title>
<para>
<command>DROP 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-altersubscription"/></member>
</simplelist>
</refsect1>
</refentry>