<listitem>
        <para>
         The primary error message and associated SQLSTATE code for the most
         recent failed query in the current <application>psql</application> session, or
         an empty string and <literal>00000</literal> if no error has occurred in
         the current session.
        </para>
       </listitem>
      </varlistentry>

      <varlistentry id="app-psql-variables-on-error-rollback">
      <term>
       <varname>ON_ERROR_ROLLBACK</varname>
       <indexterm>
        <primary>rollback</primary>
        <secondary>psql</secondary>
       </indexterm>
      </term>
        <listitem>
        <para>
        When set to <literal>on</literal>, if a statement in a transaction block
        generates an error, the error is ignored and the transaction
        continues. When set to <literal>interactive</literal>, such errors are only
        ignored in interactive sessions, and not when reading script
        files. When set to <literal>off</literal> (the default), a statement in a
        transaction block that generates an error aborts the entire
        transaction. The error rollback mode works by issuing an
        implicit <command>SAVEPOINT</command> for you, just before each command
        that is in a transaction block, and then rolling back to the
        savepoint if the command fails.
        </para>
        </listitem>
      </varlistentry>

      <varlistentry id="app-psql-variables-on-error-stop">
        <term><varname>ON_ERROR_STOP</varname></term>
        <listitem>
        <para>
        By default, command processing continues after an error.  When this
        variable is set to <literal>on</literal>, processing will instead stop
        immediately.  In interactive mode,
        <application>psql</application> will return to the command prompt;
        otherwise, <application>psql</application> will exit, returning
        error code 3 to distinguish this case from fatal error
        conditions, which are reported using error code 1.  In either case,
        any currently running scripts (the top-level script, if any, and any
        other scripts which it may have in invoked) will be terminated
        immediately.  If the top-level command string contained multiple SQL
        commands, processing will stop with the current command.
        </para>
        </listitem>
      </varlistentry>

      <varlistentry id="app-psql-variables-pipeline-command-count">
        <term><varname>PIPELINE_COMMAND_COUNT</varname></term>
        <listitem>
        <para>
        The number of commands queued in an ongoing pipeline.
        </para>
        </listitem>
      </varlistentry>

      <varlistentry id="app-psql-variables-pipeline-result-count">
        <term><varname>PIPELINE_RESULT_COUNT</varname></term>
        <listitem>
        <para>
        The number of commands of an ongoing pipeline that were followed
        by either a <command>\flushrequest</command> or a
        <command>\syncpipeline</command>, forcing the server to send the
        results. These results can be retrieved with
        <command>\getresults</command>.
        </para>
        </listitem>
      </varlistentry>

      <varlistentry id="app-psql-variables-pipeline-sync-count">
        <term><varname>PIPELINE_SYNC_COUNT</varname></term>
        <listitem>
        <para>
        The number of sync messages queued in an ongoing pipeline.
        </para>
        </listitem>
      </varlistentry>

      <varlistentry id="app-psql-variables-port">
        <term><varname>PORT</varname></term>
        <listitem>
        <para>
        The database server port to which you are currently connected.
        This is set every time you connect to a database (including
        program start-up), but can be changed or unset.
        </para>
        </listitem>
      </varlistentry>

      <varlistentry id="app-psql-variables-prompt">
        <term><varname>PROMPT1</varname></term>
        <term><varname>PROMPT2</varname></term>