P
>    If no output column name is specified using <TT
CLASS="LITERAL"
>AS</TT
>,
    the system assigns a default column name.  For simple column references,
    this is the name of the referenced column.  For function
    calls, this is the name of the function.  For complex expressions,
    the system will generate a generic name.
   </P
><P
>    The <TT
CLASS="LITERAL"
>AS</TT
> keyword is optional, but only if the new column
    name does not match any
    <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> 