array of <structname>PQconninfoOption</structname>
       structures, which ends with an entry having a null <structfield>keyword</structfield>
       pointer. All notes above for <xref linkend="libpq-PQconndefaults"/> also
       apply to the result of <xref linkend="libpq-PQconninfo"/>.
      </para>

     </listitem>
    </varlistentry>


    <varlistentry id="libpq-PQconninfoParse">
     <term><function>PQconninfoParse</function><indexterm><primary>PQconninfoParse</primary></indexterm></term>
     <listitem>
      <para>
       Returns parsed connection options from the provided connection string.

<synopsis>
PQconninfoOption *PQconninfoParse(const char *conninfo, char **errmsg);
</synopsis>
      </para>

      <para>
       Parses a connection string and returns the resulting options as an
       array; or returns <symbol>NULL</symbol> if there is a problem with the connection
       string.  This function can be used to extract
       the <xref linkend="libpq-PQconnectdb"/> options in the provided
       connection string.  The return value points to an array of
       <structname>PQconninfoOption</structname> structures, which ends
       with an entry having a null <structfield>keyword</structfield> pointer.
      </para>

      <para>
       All legal options will be present in the result array, but the
       <literal>PQconninfoOption</literal> for any option not present
       in the connection string will have <literal>val</literal> set to
       <literal>NULL</literal>; default values are not inserted.
      </para>

      <para>
       If <literal>errmsg</literal> is not <symbol>NULL</symbol>, then <literal>*errmsg</literal> is set
       to <symbol>NULL</symbol> on success, else to a <function>malloc</function>'d error string explaining
       the problem.  (It is also possible for <literal>*errmsg</literal> to be
       set to <symbol>NULL</symbol> and the function to return <symbol>NULL</symbol>;
       this indicates an out-of-memory condition.)
      </para>

      <para>
       After processing the options array, free it by passing it to
       <xref linkend="libpq-PQconninfoFree"/>.  If this is not done, some memory
       is leaked for each call to <xref linkend="libpq-PQconninfoParse"/>.
       Conversely, if an error occurs and <literal>errmsg</literal> is not <symbol>NULL</symbol>,
       be sure to free the error string using <xref linkend="libpq-PQfreemem"/>.
      </para>

   </listitem>
    </varlistentry>

    <varlistentry id="libpq-PQfinish">
     <term><function>PQfinish</function><indexterm><primary>PQfinish</primary></indexterm></term>
     <listitem>
      <para>
       Closes  the  connection to the server.  Also frees
       memory used by the <structname>PGconn</structname> object.
<synopsis>
void PQfinish(PGconn *conn);
</synopsis>
      </para>

      <para>
       Note that even if the server connection attempt fails (as
       indicated by <xref linkend="libpq-PQstatus"/>), the application should call <xref linkend="libpq-PQfinish"/>
       to free the memory used by the <structname>PGconn</structname> object.
       The <structname>PGconn</structname> pointer must not be used again after
       <xref linkend="libpq-PQfinish"/> has been called.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="libpq-PQreset">
     <term><function>PQreset</function><indexterm><primary>PQreset</primary></indexterm></term>
     <listitem>
      <para>
       Resets the communication channel to the server.
<synopsis>
void PQreset(PGconn *conn);
</synopsis>
      </para>

      <para>
       This function will close the connection
       to the server and attempt to establish a new
       connection, using all the same
       parameters previously used.  This might be useful for
       error recovery if a working connection is lost.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="libpq-PQresetStart">
     <term><function>PQresetStart</function><indexterm><primary>PQresetStart</primary></indexterm></term>