taken to ensure that WAL archives from separate
    primary servers do not become mixed together or confused. The archive
    need not be large if it is only required for standby operation.
   </P
><P
>    The magic that makes the two loosely coupled servers work together is
    simply a <TT
CLASS="VARNAME"
>restore_command</TT
> used on the standby that,
    when asked for the next WAL file, waits for it to become available from
    the primary. The <TT
CLASS="VARNAME"
>restore_command</TT
> is specified i