 the same as the <TT
CLASS="LITERAL"
>include</TT
> directive, except for the behavior
         when the referenced file does not exist or cannot be read.  A regular
         <TT
CLASS="LITERAL"
>include</TT
> will consider this an error condition, but
         <TT
CLASS="LITERAL"
>include_if_exists</TT
> merely logs a message and continues
         processing the referencing configuration file.
     </P
><P
>      
        The <TT
CLASS="FILENAME"
>postgresql.conf</TT
> file can also contain
        <TT
CL