 though this requires custom development, and changes
    will still only become visible to hot standby queries after a full WAL
    file has been shipped.
   </P
><P
>    An external program can call the <CODE
CLASS="FUNCTION"
>pg_xlogfile_name_offset()</CODE
>
    function (see <A
HREF="functions-admin.html"
>Section 9.26</A
>)
    to find out the file name and the exact byte offset within it of
    the current end of WAL.  It can then access the WAL file directly
    and copy the data from the last known