n.
    In fact, the command type is not needed by view rules, but the result
    relation may affect the way in which the query rewriter works, because
    special care needs to be taken if the result relation is a view.</P
><P
>    There are only a few differences between a query tree for a
    <TT
CLASS="COMMAND"
>SELECT</TT
> and one for any other
    command. Obviously, they have a different command type and for a
    command other than a <TT
CLASS="COMMAND"
>SELECT</TT
>, the result
    relation points