<manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
   <refname>dblink_error_message</refname>
   <refpurpose>gets last error message on the named connection</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
<synopsis>
dblink_error_message(text connname) returns text
</synopsis>
  </refsynopsisdiv>

  <refsect1>
   <title>Description</title>

   <para>
    <function>dblink_error_message</function> fetches the most recent remote
    error message for a given connection.
   </para>
  </refsect1>

  <refsect1>
   <title>Arguments</title>

   <variablelist>
    <varlistentry>
     <term><parameter>connname</parameter></term>
     <listitem>
      <para>
       Name of the connection to use.
      </para>
     </listitem>
    </varlistentry>
   </variablelist>
  </refsect1>

  <refsect1>
   <title>Return Value</title>

   <para>
    Returns last error message, or <literal>OK</literal> if there has been
    no error in this connection.
   </para>
  </refsect1>

  <refsect1>
   <title>Notes</title>

   <para>
    When asynchronous queries are initiated by
    <function>dblink_send_query</function>, the error message associated with
    the connection might not get updated until the server's response message
    is consumed. This typically means that <function>dblink_is_busy</function>
    or <function>dblink_get_result</function> should be called prior to
    <function>dblink_error_message</function>, so that any error generated by
    the asynchronous query will be visible.
   </para>
  </refsect1>

  <refsect1>
   <title>Examples</title>

<programlisting>
SELECT dblink_error_message('dtest1');
</programlisting>
  </refsect1>
 </refentry>

 <refentry id="contrib-dblink-send-query">
  <indexterm>
   <primary>dblink_send_query</primary>
  </indexterm>

  <refmeta>
   <refentrytitle>dblink_send_query</refentrytitle>
   <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
   <refname>dblink_send_query</refname>
   <refpurpose>sends an async query to a remote database</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
<synopsis>
dblink_send_query(text connname, text sql) returns int
</synopsis>
  </refsynopsisdiv>

  <refsect1>
   <title>Description</title>

   <para>
    <function>dblink_send_query</function> sends a query to be executed
    asynchronously, that is, without immediately waiting for the result.
    There must not be an async query already in progress on the
    connection.
   </para>

   <para>
    After successfully dispatching an async query, completion status
    can be checked with <function>dblink_is_busy</function>, and the results
    are ultimately collected with <function>dblink_get_result</function>.
    It is also possible to attempt to cancel an active async query
    using <function>dblink_cancel_query</function>.
   </para>
  </refsect1>

  <refsect1>
   <title>Arguments</title>

   <variablelist>
    <varlistentry>
     <term><parameter>connname</parameter></term>
     <listitem>
      <para>
       Name of the connection to use.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term><parameter>sql</parameter></term>
     <listitem>
      <para>
       The SQL statement that you wish to execute in the remote database,
       for example <literal>select * from pg_class</literal>.
      </para>
     </listitem>
    </varlistentry>
   </variablelist>
  </refsect1>

  <refsect1>
   <title>Return Value</title>

   <para>
    Returns 1 if the query was successfully dispatched, 0 otherwise.
   </para>
  </refsect1>

  <refsect1>
   <title>Examples</title>

<programlisting>
SELECT dblink_send_query('dtest1', 'SELECT * FROM foo WHERE f1 &lt; 3');
</programlisting>
  </refsect1>
 </refentry>

 <refentry id="contrib-dblink-is-busy">
  <indexterm>
   <primary>dblink_is_busy</primary>
  </indexterm>

  <refmeta>
   <refentrytitle>dblink_is_busy</refentrytitle>
   <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
   <refname>dblink_is_busy</refname>
   <refpurpose>checks if connection is busy