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

<refentry id="SQL-ROLLBACK-PREPARED">
 <refmeta>
  <refentrytitle>ROLLBACK PREPARED</refentrytitle>
  <manvolnum>7</manvolnum>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>ROLLBACK PREPARED</refname>
  <refpurpose>cancel a transaction that was earlier prepared for two-phase commit</refpurpose>
 </refnamediv>

 <indexterm zone="sql-rollback-prepared">
  <primary>ROLLBACK PREPARED</primary>
 </indexterm>

 <refsynopsisdiv>
<synopsis>
ROLLBACK PREPARED <replaceable class="PARAMETER">transaction_id</replaceable>
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>ROLLBACK PREPARED</command> rolls back a transaction that is in
   prepared state.
  </para>
 </refsect1>

 <refsect1>
  <title>Parameters</title>

  <variablelist>
   <varlistentry>
    <term><replaceable class="PARAMETER">transaction_id</replaceable></term>
    <listitem>
     <para>
      The transaction identifier of the transaction that is to be
      rolled back.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1>
  <title>Notes</title>

  <para>
   To roll back a prepared transaction, you must be either the same user that
   executed the transaction originally, or a superuser.  But you do not
   have to be in the same session that executed the transaction.
  </para>

  <para>
   This command cannot be executed inside a transaction block. The prepared
   transaction is rolled back immediately.
  </para>

  <para>
   All currently available prepared transactions are listed in the
   <link linkend="view-pg-prepared-xacts"><structname>pg_prepared_xacts</structname></link>
   system view.
  </para>
 </refsect1>

 <refsect1 id="sql-rollback-prepared-examples">
  <title id="sql-rollback-prepared-examples-title">Examples</title>
  <para>
   Roll back the transaction identified by the transaction
   identifier <literal>foobar</>:

<programlisting>
ROLLBACK PREPARED 'foobar';
</programlisting></para>

 </refsect1>

 <refsect1>
  <title>Compatibility</title>

  <para>
   <command>ROLLBACK PREPARED</command> is a
   <productname>PostgreSQL</productname> extension.  It is intended for use by
   external transaction management systems, some of which are covered by
   standards (such as X/Open XA), but the SQL side of those systems is not
   standardized.
  </para>
 </refsect1>

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

  <simplelist type="inline">
   <member><xref linkend="sql-prepare-transaction"></member>
   <member><xref linkend="sql-commit-prepared"></member>
  </simplelist>
 </refsect1>

</refentry>
